[to delete] Try to repro BackgroundTask crash

- Reports of OSBackgroundTaskHandlerImpl.beginBackgroundTask crashing with trace
- objc_msgSend + 8
- [__NSDictionaryM setObject:forKeyedSubscript:] + 484

That was reproduced by passing in a nil taskIdentifier, but how could that happen?

iOS_SDK/OneSignalSDK/Source/OSBackgroundTaskHandlerImpl.m

@@ -51,8 +51,31 @@ - (void)beginBackgroundTask:(NSString * _Nonnull)taskIdentifier {
         [self endBackgroundTask:taskIdentifier];
     }];
     tasks[taskIdentifier] = [NSNumber numberWithUnsignedLong:uiIdentifier];
+    [self tryToReproCrash:taskIdentifier];
 }
 
+- (void)tryToReproCrash:(NSString*)taskIdentifier {
+    // 1. This is fine, doesnt crash
+    tasks[taskIdentifier] = [NSNumber numberWithUnsignedLong:nil];
+
+    // 2. This is apparently fine too, doesnt crash
+    tasks[taskIdentifier] = nil;
+
+    // 3. This is fine too
+    tasks = nil;
+    tasks[taskIdentifier] = [NSNumber numberWithUnsignedLong:5];
+
+    // 4. This crashes with the stacktrace
+
+    tasks = [NSMutableDictionary new];
+    taskIdentifier = nil;
+    tasks[taskIdentifier] = [NSNumber numberWithUnsignedLong:5];
+    // objc_msgSend$callStackReturnAddresses
+    // 0x00000001a410a048 in -[__NSDictionaryM setObject:forKeyedSubscript:] ()
+    // 0x0000000101b430b8 in -[OSBackgroundTaskHandlerImpl beginBackgroundTask:] at OSBackgroundTaskHandlerImpl.m:66
+
+    NSLog(@"Tasks: %@", tasks);
+}
 - (void)endBackgroundTask:(NSString * _Nonnull)taskIdentifier {
     UIBackgroundTaskIdentifier uiIdentifier = [[tasks objectForKey:taskIdentifier] unsignedLongValue];
     [OneSignalLog onesignalLog:ONE_S_LL_DEBUG