Nightly builds might get signed with a different key for each build

[Torsten Grote]

This makes it impossible to update to new versions without uninstalling old versions before.

[akwizgran]

🤦

[Torsten Grote]

Due to wardvl/f-droid-nightly-action#3 we weren't letting fdroidserver resign our APK. However, the persistent keystore only got extracted after gradle had already signed the build.

Let's see if those two commits have fixed it:

• 443be15
• 8d15e1d

[Torsten Grote]

Looks like that did the trick. The last two merges were signed with the same key as a79d21b.