cert_additional_names changes are not cleaned up safely

[Ryan Finnie]

Formerly "cert_additional_names=host.example.com=admin.host.example.com", I flipped them around to "cert_additional_names=admin.host.example.com=host.example.com" (changing cert_auth_pairs at the same time). /etc/autocert/apache2/host.example.com.ini did indeed disappear and was replaced with /etc/autocert/apache2/admin.host.example.com.ini, but after the run, the units were left with this for the actual certs:

0 lrwxrwxrwx 1 root root 35 Sep 6 00:25 host.example.com-chain.pem -> admin.host.example.com-chain.pem
0 lrwxrwxrwx 1 root root 29 Sep 6 00:25 host.example.com.crt -> admin.host.example.com.crt
0 lrwxrwxrwx 1 root root 29 Sep 6 00:25 host.example.com.key -> admin.host.example.com.key
0 lrwxrwxrwx 1 root root 29 Sep 3 07:37 admin.host.example.com-chain.pem -> host.example.com-chain.pem
0 lrwxrwxrwx 1 root root 23 Sep 3 07:37 admin.host.example.com.crt -> host.example.com.crt
0 lrwxrwxrwx 1 root root 23 Sep 3 07:37 admin.host.example.com.key -> host.example.com.key