Change default port of backend to 7007 due to MacOS Control Center update

Signed-off-by: Otto Sichert <git@ottosichert.de>

docs/auth/gitlab/provider.md

@@ -17,7 +17,7 @@ should point to your Backstage backend auth handler.
 Settings for local development:
 
 - Name: Backstage (or your custom app name)
-- Redirect URI: `http://localhost:7000/api/auth/gitlab/handler/frame`
+- Redirect URI: `http://localhost:7007/api/auth/gitlab/handler/frame`
 - Scopes: read_user
 
 ## Configuration