Can't create new invites when anyone-can-join link has expired and 1 member in group

[taoeffect]

Problem

If someone created a group and didn't invite anyone, and let the anyone-can-join invite expired, we can get stuck.

Attempting to create a new invite fails, and for some reason the button says "Send Invitation" instead of "Next":

If at this prompt we press the Enter key, we get this mess:

But still, no invite can be created.

Solution

I think in this situation we really want to do two things:

1. For existing groups, we don't want them to get stuck in this situation, so we should make it possible to still create new invites. In fact, why don't we just automatically recreate a new anyone-can-join invite link and use that?
2. For new groups, perhaps we shouldn't let the anyone-can-join invite expire. Set a very long expiry time for it (e.g. 20 years into the future).