improve comment why we can change \ to /

Author: Lubos Kosco

src/org/opensolaris/opengrok/index/IndexDatabase.java

@@ -1079,6 +1079,7 @@ public static Definitions getDefinitions(File file)
         RuntimeEnvironment env = RuntimeEnvironment.getInstance();
         String path = env.getPathRelativeToSourceRoot(file, 0);
         //sanitize windows path delimiters
+        //in order not to conflict with Lucene escape character
         path=path.replace("\\", "/");
 
         IndexReader ireader = getIndexReader(path);