Fixing small space missing in sample config file (#28967)

custom/conf/app.example.ini

@@ -431,7 +431,7 @@ SECRET_KEY =
 ;SECRET_KEY_URI = file:/etc/gitea/secret_key
 ;;
 ;; Secret used to validate communication within Gitea binary.
-INTERNAL_TOKEN=
+INTERNAL_TOKEN =
 ;;
 ;; Alternative location to specify internal token, instead of this file; you cannot specify both this and INTERNAL_TOKEN, and must pick one
 ;INTERNAL_TOKEN_URI = file:/etc/gitea/internal_token