More consistent index name in the error message

Author: atapin

server/src/main/java/org/elasticsearch/index/IndexNotFoundException.java

@@ -46,7 +46,7 @@ public IndexNotFoundException(Index index) {
     }
 
     public IndexNotFoundException(Index index, Throwable cause) {
-        super("no such index " + index.toString(), cause);
+        super("no such index [" + index.getName() + "]", cause);
         setIndex(index);
     }