CI: Bump image, now has -dev and gcc
CI: Bump image, now has -dev and gcc

Also, use a specific tag instead of "latest" to avoid breaking old
tags/commits when updating the image.

f-droid/fdroidserver,f-droid/fdroidserver,f-droid/fdroid-server,f-droid/fdroid-server,fdroidtravis/fdroidserver,fdroidtravis/fdroidserver,f-droid/fdroid-server,f-droid/fdroidserver,fdroidtravis/fdroidserver,f-droid/fdroid-server,f-droid/fdroidserver,fdroidtravis/fdroidserver,f-droid/fdroid-server,f-droid/fdroidserver