Update Classifier.java

I fixed below error msg though updating Classifier.java.

 -- error msg  ---
Exception in thread "main" java.lang.IllegalStateException: TokenStream contract violation: close() call missing
	at org.apache.lucene.analysis.Tokenizer.setReader(Tokenizer.java:89)
	at org.apache.lucene.analysis.Analyzer$TokenStreamComponents.setReader(Analyzer.java:307)
	at org.apache.lucene.analysis.standard.StandardAnalyzer$1.setReader(StandardAnalyzer.java:120)
	at org.apache.lucene.analysis.Analyzer.tokenStream(Analyzer.java:145)
	at Classifier.main(Classifier.java:115)