Fix: crmd: Disconnect the relevant remote proxies as well when disconnecting a remote node

Previously, the relevant remote proxies would still exist even if a
remote node was already disconnected. So whenever there was an event, it
would still trigger remote_proxy_dispatch_internal(). Especially if the
remote node was unexpectedly disconnected, lrmd_tls_send() would fail to
relay the event and call lrmd_tls_disconnect() again. It actually always
occurred when reconnecting to the remote node, which basically made
reconnecting impossible.