Remove useless variable

roles/matrix-synapse/vars/main.yml

@@ -6,7 +6,6 @@ matrix_synapse_federation_api_url_endpoint_public: "https://{{ matrix_server_fqn
 # Tells whether this role had executed or not. Toggled to `true` during runtime.
 matrix_synapse_role_executed: false
 
-matrix_synapse_media_store_parent_path: "{{ matrix_synapse_media_store_path|dirname }}"
 matrix_synapse_media_store_directory_name: "{{ matrix_synapse_media_store_path|basename }}"
 
 # A Synapse generic worker can handle both federation and client-server API endpoints.