add comma

Author: Vladimir Kotal

opengrok-web/src/main/java/org/opengrok/web/api/v1/filter/IncomingFilter.java

@@ -18,7 +18,7 @@
  */
 
 /*
- * Copyright (c) 2018, 2020 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
  */
 package org.opengrok.web.api.v1.filter;