Maildrop 0.9.22

Automatic updates repaired.

Maildrop's update-signing key had to be replaced after the original key was lost in a Mac rebuild — that's what caused the "improperly signed update" error on 0.9.19–0.9.21. This version is signed with the new key. Because your current copy only trusts the old key, download this one update manually from maildrop.serkowski.net; after that, automatic updates work normally again.