Use the source's sync state and not mine when processing sjoins to determine whether or not to sync the channel on creation, instead sync it when the server syncs.

src/channels.cpp

@@ -90,6 +90,7 @@ void Channel::Reset()
 
 void Channel::Sync()
 {
+	syncing = false;
 	FOREACH_MOD(OnChannelSync, (this));
 }