title: Log4j2 encoding issue
body: <p>When I try to run Elasticsearch on Windows 10 as main language is English, everything works fine. But if I change the main language as Turkish, I get error messages as: </p>
  
  <pre><code>2018-07-26 14:42:39,485 main ERROR Unable to locate plugin type for IfFileName
  2018-07-26 14:42:39,633 main ERROR Unable to locate plugin for IfAccumulatedFileSize
  2018-07-26 14:42:39,634 main ERROR Unable to locate plugin for IfFileName
  2018-07-26 14:42:39,637 main ERROR Unable to invoke factory method in class org.apache.logging.log4j.core.appender.rolling.action.DeleteAction for element Delete: java.lang.NullPointerException java.lang.NullPointerException
      at org.apache.logging.log4j.core.config.plugins.visitors.PluginElementVisitor.findNamedNode(PluginElementVisitor.java:103)
      at org.apache.logging.log4j.core.config.plugins.visitors.PluginElementVisitor.visit(PluginElementVisitor.java:87)
      at org.apache.logging.log4j.core.config.plugins.util.PluginBuilder.generateParameters(PluginBuilder.java:248)
      at org.apache.logging.log4j.core.config.plugins.util.PluginBuilder.build(PluginBuilder.java:135)
      at org.apache.logging.log4j.core.config.AbstractConfiguration.createPluginObject(AbstractConfiguration.java:958)
      at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:898)
      at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:890)
      at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:890)
      at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:890)
      at org.apache.logging.log4j.core.config.AbstractConfiguration.doConfigure(AbstractConfiguration.java:513)
      at org.apache.logging.log4j.core.config.AbstractConfiguration.initialize(AbstractConfiguration.java:237)
      at org.apache.logging.log4j.core.config.AbstractConfiguration.start(AbstractConfiguration.java:249)
      at org.apache.logging.log4j.core.LoggerContext.setConfiguration(LoggerContext.java:545)
      at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:261)
      at org.elasticsearch.common.logging.LogConfigurator.configure(LogConfigurator.java:163)
      at org.elasticsearch.common.logging.LogConfigurator.configure(LogConfigurator.java:119)
      at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:291)
      at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:121)
      at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:112)
      at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86)
      at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124)
      at org.elasticsearch.cli.Command.main(Command.java:90)
      at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92)
      at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:85)
  
  2018-07-26 14:42:39,645 main ERROR Null object returned for Delete in DefaultRolloverStrategy.
  </code></pre>
  
  <p>So it seem like a charset problem. The file is encoded as <code>UTF-8</code>, I check it with Notepad++. Elasticsearch has JVM option <code>-Dfile.encoding=UTF-8</code>. I double checked the log4j2.properties file and <code>IfFileName</code> has no space after it.</p>
  
  <p>And if I change <code>IfFileName</code> as <code>ıfFileName</code> (which <code>ı</code> is a Turkish character - lower I) error becomes: </p>
  
  <pre><code>2018-07-26 14:54:25,819 main ERROR Unable to locate plugin type for Ä±fFileName
  </code></pre>
  
  <p>Does anyone have an idea about how to fix that?</p>