Closes #2570. CC #2561: It also works with the initial connect now. But the address being updated always seems to be the Internet address at that point.

0d413d89d815834047d0290136940832940f4949 broke it. You can no longer use /help, etc. if they are listed as a server-side command. You can reproduce this bug on 152.89.105.108:5555 f.e.

This was supposed to fix #2573, but turns out the server doesn't even handle command messages at all. I don't think a fallback to a chat message is desirable here, but it's up to you.