ssb: Sync on demand fixes. Avoid keeping message streams live in this mode.

src/ssb.c

@@ -4323,3 +4323,8 @@ bool tf_ssb_tunnel_create(tf_ssb_t* ssb, const char* portal_id, const char* targ
 	}
 	return connection != NULL;
 }
+
+int tf_ssb_connection_get_flags(tf_ssb_connection_t* connection)
+{
+	return connection->flags;
+}