fix popuplevel should be "-1" when not present

Author: dmendez

common/src/main/java/com/genexus/internet/GXNavigationHelper.java

@@ -148,6 +148,7 @@ static public String getUrlComponent(String url, String key)
 
         static public String getUrlPopupLevel(String url)
         {
-            return getUrlComponent( url, POPUP_LEVEL);
+            String result = getUrlComponent( url, POPUP_LEVEL);
+            return result.isEmpty() ? "-1":result;
         }
     }