knownnetworks: remove redundant ops->remove()

The remove op was being called inside known_networks_remove, which only
gets called from L_DIR_WATCH events. In this case the actual provisioning
has already been removed. Calling remove() again causes the op
implementation to then try and remove the file that no longer exists.

src/knownnetworks.c

@@ -566,8 +566,6 @@ void known_networks_remove(struct network_info *network)
 				known_networks_watch_func_t,
 				KNOWN_NETWORKS_EVENT_REMOVED, network);
 
-	network->ops->remove(network);
-
 	network_info_free(network);
 }