Update src/Services/Webhooks/Webhooks.API/Controllers/WebhooksController.cs

Co-authored-by: Reuben Bond <203839+ReubenBond@users.noreply.github.com>

src/Services/Webhooks/Webhooks.API/Controllers/WebhooksController.cs

@@ -71,7 +71,7 @@ public class WebhooksController : ControllerBase
         }
         else
         {
-            return StatusCode(StatusCodes.Status418ImATeapot, "Grant url can't be validated");
+            return StatusCode(StatusCodes.Status418ImATeapot, "Grant URL invalid");
         }
     }