Restore support for appservice and user_dir workers

roles/matrix-synapse/vars/workers.yml

@@ -90,7 +90,9 @@ matrix_synapse_workers_generic_worker_endpoints:
 #  - ^/_matrix/client/(api/v1|r0|v3|unstable)/presence/
 
   # User directory search requests
-  - ^/_matrix/client/(r0|v3|unstable)/user_directory/search$
+  # Any worker can handle these, but we have a dedicated user_dir worker for this,
+  # so we'd like for other generic workers to not try and capture these requests.
+  # - ^/_matrix/client/(r0|v3|unstable)/user_directory/search$
 
   # Additionally, the following REST endpoints can be handled for GET requests: