Updating to Lemmy 0.18.1-rc.4 / UI 0.18.1-rc.7 - Success

I'm about to perform this update in the next 10 minutes, all things going well there should be no downtime/instability.

I don't normally update to rc releases but it's worth it in this case as there are several important fixes:

• Captcha is working again
• "Reset password" is rate limited
• UI looks better ... and more.

The DB is backed up, I'll post an update here once everything's done.