Remove leading slash from callback path

This is added in core urls for the notifications namespace.

Author: steventux

manage_breast_screening/notifications/urls.py

@@ -6,7 +6,7 @@
 
 urlpatterns = [
     path(
-        "/message-status/create",
+        "message-status/create",
         views.create_message_status,
         name="create_message_status",
     ),