Update roles/custom/matrix-synapse/templates/synapse/homeserver.yaml.j2

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

roles/custom/matrix-synapse/templates/synapse/homeserver.yaml.j2

@@ -2630,7 +2630,7 @@ user_directory:
     # Uncomment to return search results containing all known users, even if that
     # user does not share a room with the requester.
     #
-    search_all_users: {{ matrix_synapse_search_all_users|to_json }}
+    search_all_users: {{ matrix_synapse_user_directory_search_all_users | to_json }}
 
     # Defines whether to prefer local users in search query results.
     # If True, local users are more likely to appear above remote users