APP_SERVICE_PREFIX is never used; don't bother

synapse/api/urls.py

@@ -25,4 +25,3 @@ SERVER_KEY_PREFIX = "/_matrix/key/v1"
 SERVER_KEY_V2_PREFIX = "/_matrix/key/v2"
 MEDIA_PREFIX = "/_matrix/media/r0"
 LEGACY_MEDIA_PREFIX = "/_matrix/media/v1"
-APP_SERVICE_PREFIX = "/_matrix/appservice/v1"