[#351] Disable nu.validator language detection to fix random NPE

[tkaik]

Description

enableLanguageDetection flag set to false for SimpleDocumentValidator object (NuValidator).

Motivation and Context

Related issue: #351

Following error is sometimes thrown in worker logs:

2018-09-17T12:31:59,018 | ERROR | com.cognifide.aet.worker | ComparatorDispatcherImpl           68 | Comparator{type=source, filters=[], parameters={comparator=w3c-html5}} throw error:
com.cognifide.aet.job.api.exceptions.ProcessingException: null
        at com.cognifide.aet.job.common.comparators.w3chtml5.W3cHtml5Comparator.compare(W3cHtml5Comparator.java:75) ~[?:?]
        at com.cognifide.aet.worker.impl.ComparatorDispatcherImpl.run(ComparatorDispatcherImpl.java:66) [52:com.cognifide.aet.worker:3.0.0]
        at com.cognifide.aet.worker.listeners.ComparatorMessageListenerImpl.onMessage(ComparatorMessageListenerImpl.java:95) [52:com.cognifide.aet.worker:3.0.0]
        at org.apache.activemq.ActiveMQMessageConsumer.dispatch(ActiveMQMessageConsumer.java:1404) [127:org.apache.activemq.activemq-osgi:5.15.2]
        at org.apache.activemq.ActiveMQSessionExecutor.dispatch(ActiveMQSessionExecutor.java:131) [127:org.apache.activemq.activemq-osgi:5.15.2]
        at org.apache.activemq.ActiveMQSessionExecutor.iterate(ActiveMQSessionExecutor.java:202) [127:org.apache.activemq.activemq-osgi:5.15.2]
        at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:133) [127:org.apache.activemq.activemq-osgi:5.15.2]
        at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:48) [127:org.apache.activemq.activemq-osgi:5.15.2]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:?]
        at java.lang.Thread.run(Thread.java:748) [?:?]
Caused by: java.lang.NullPointerException
        at com.cybozu.labs.langdetect.DetectorFactory.addProfile(DetectorFactory.java:135) ~[?:?]
        at com.cybozu.labs.langdetect.DetectorFactory.loadProfile(DetectorFactory.java:108) ~[?:?]
        at nu.validator.xml.LanguageDetectingXMLReaderWrapper.initialize(LanguageDetectingXMLReaderWrapper.java:188) ~[?:?]
        at nu.validator.validation.SimpleDocumentValidator.<init>(SimpleDocumentValidator.java:218) ~[?:?]
        at nu.validator.validation.SimpleDocumentValidator.<init>(SimpleDocumentValidator.java:154) ~[?:?]
        at com.cognifide.aet.job.common.comparators.w3chtml5.wrapper.NuValidatorWrapper.setupAndValidate(NuValidatorWrapper.java:58) ~[?:?]
        at com.cognifide.aet.job.common.comparators.w3chtml5.wrapper.NuValidatorWrapper.validate(NuValidatorWrapper.java:48) ~[?:?]
        at com.cognifide.aet.job.common.comparators.w3chtml5.W3cHtml5Comparator.compare(W3cHtml5Comparator.java:70) ~[?:?]

We don't know the root cause of this error and it's hard to provide any reproduction steps - it seems like it's randomly thrown for few different URLs for some test suites. The error is thrown in the language detection library (dependency of nu validator) - disabling this feature seems to be fixing the issue.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

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I hereby agree to the terms of the AET Contributor License Agreement.

[malaskowski]

Let's update changelog before merging this issue.