No jira, added missing mention of mapping file to help message.
diff --git a/corpus-server-tools/src/main/java/org/apache/opennlp/corpus_server/tools/CreateCorpus.java b/corpus-server-tools/src/main/java/org/apache/opennlp/corpus_server/tools/CreateCorpus.java
index b022dc7..34a56ed 100644
--- a/corpus-server-tools/src/main/java/org/apache/opennlp/corpus_server/tools/CreateCorpus.java
+++ b/corpus-server-tools/src/main/java/org/apache/opennlp/corpus_server/tools/CreateCorpus.java
@@ -35,7 +35,7 @@
 	public static void main(String[] args) throws Exception {
 		
 		if (args.length != 4) {
-			System.out.println("CreateCorpus address corpusName typeSystemFile");
+			System.out.println("CreateCorpus address corpusName typeSystemFile mappingFile");
 			System.exit(-1);
 		}