throw exception for unknown token in RestIndexPutAliasAction

Author: 广富

server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestIndexPutAliasAction.java

@@ -89,6 +89,8 @@ public RestChannelConsumer prepareRequest(final RestRequest request, final NodeC
  if ("filter".equals(currentFieldName)) {
  filter = parser.mapOrdered();
  }
+ } else {
+ throw new IllegalArgumentException("Unknown token [" + token + "]");
  }
  }
  }