Fix NPE in the reactor-netty plugin

[jaehong-kim]

Fix NPE in the reactor-netty plugin

The versions affected by this bug are 2.5.1 and 2.5.2.

Related Logs

WARN  OHandlerObserverOnStateChangeInterceptor -- BEFORE. Caused:Cannot invoke "com.navercorp.pinpoint.plugin.reactor.netty.HttpCallContext.getWriteElapsedTime()" because "httpCallContext" is null
java.lang.NullPointerException: Cannot invoke "com.navercorp.pinpoint.plugin.reactor.netty.HttpCallContext.getWriteElapsedTime()" because "httpCallContext" is null
	at com.navercorp.pinpoint.plugin.reactor.netty.interceptor.HttpIOHandlerObserverOnStateChangeInterceptor.doInBeforeTrace(HttpIOHandlerObserverOnStateChangeInterceptor.java:98) ~[pinpoint-reactor-netty-plugin-2.5.2.jar:2.5.2]
	at com.navercorp.pinpoint.bootstrap.interceptor.AsyncContextSpanEventSimpleAroundInterceptor.before(AsyncContextSpanEventSimpleAroundInterceptor.java:68) ~[?:2.5.2]
	at com.navercorp.pinpoint.bootstrap.interceptor.ExceptionHandleAroundInterceptor.before(ExceptionHandleAroundInterceptor.java:35) ~[?:2.5.2]
	at reactor.netty.http.client.HttpClientConnect$HttpIOHandlerObserver.onStateChange(HttpClientConnect.java) ~[reactor-netty-http-1.0.31.jar!/:1.0.31]
	at reactor.netty.ReactorNetty$CompositeConnectionObserver.onStateChange(ReactorNetty.java:707) ~[reactor-netty-core-1.0.31.jar!/:1.0.31]
	at reactor.netty.resources.DefaultPooledConnectionProvider$DisposableAcquire.onStateChange(DefaultPooledConnectionProvider.java:193) ~[reactor-netty-core-1.0.31.jar!/:1.0.31]
	at reactor.netty.resources.DefaultPooledConnectionProvider$PooledConnection.onStateChange(DefaultPooledConnectionProvider.java:409) ~[reactor-netty-core-1.0.31.jar!/:1.0.31]
	at reactor.netty.channel.ChannelOperationsHandler.channelInactive(ChannelOperationsHandler.java:76) ~[reactor-netty-core-1.0.31.jar!/:1.0.31]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:305) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:281) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:274) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelInactive(CombinedChannelDuplexHandler.java:418) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.channelInputClosed(ByteToMessageDecoder.java:411) ~[netty-codec-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.channelInactive(ByteToMessageDecoder.java:376) ~[netty-codec-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.handler.codec.http.HttpClientCodec$Decoder.channelInactive(HttpClientCodec.java:329) ~[netty-codec-http-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.CombinedChannelDuplexHandler.channelInactive(CombinedChannelDuplexHandler.java:221) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:303) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:281) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:274) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelInactive(DefaultChannelPipeline.java:1405) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:301) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:281) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.DefaultChannelPipeline.fireChannelInactive(DefaultChannelPipeline.java:901) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.AbstractChannel$AbstractUnsafe$7.run(AbstractChannel.java:813) ~[netty-transport-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:174) ~[netty-common-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:167) ~[netty-common-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470) ~[netty-common-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:403) ~[netty-transport-classes-epoll-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.91.Final.jar!/:4.1.91.Final]
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.91.Final.jar!/:4.1.91.Final]
	at java.lang.Thread.run(Thread.java:833) ~[?:?]

[jaehong-kim]

Applied to 2.5.3-SNAPSHOT