checkupdates: let Tags detect subdir changes
checkupdates: let Tags detect subdir changes

Up until now, this was done only if no overall version could be found. But in
tags, we would get stuck with an old version from an old tag and not see
subdir changes in new tags.

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