buildserver: strip extraneous packages installed in Vagrant base box
buildserver: strip extraneous packages installed in Vagrant base box

The official Debian Vagrant box seems to be a "batteries included" kind of
thing.  The buildserver should be as small as possible, so this removes all
the extraneous packages I could find in the Vagrant basebox.

f-droid/fdroidserver,f-droid/fdroidserver,f-droid/fdroidserver,f-droid/fdroidserver,f-droid/fdroidserver