Due to reversed conditionals, it wasn't being generated properly.
This also actually fixes its generation in librb by just copying the
Charybdis version. Unbundlers will want to take note of this.
we do this by removing the uname usage everywhere: it is not actually
used at runtime at all.
we keep the timestamp, because it is actually used in user_welcome()
but allow it to be overriden.
ideally, that timestamp would be completely removed, but I am not sure
what to put in its place, or if it would break some mysterious RFC (or
client!) if we remove that announcement.