MAGETWO-56317: [GitHub] -[2.1.0] underscore in site url breaks admin redirect...

MAGETWO-56317: [GitHub] -[2.1.0] underscore in site url breaks admin redirect - The page isn't redirecting properly #5809

setup/src/Magento/Setup/Controller/UrlCheck.php

@@ -52,6 +52,6 @@ class UrlCheck extends AbstractActionController
             }
         }
 
-        return new JsonModel(array_merge($result));
+        return new JsonModel($result);
     }
 }