Code review comment for ~ahasenack/ubuntu/+source/openssh:openssh-split-unique-gssapi

Thanks for this work Andreas - esp. on the test cases! Aside from a couple of nits inline, one concern I have is that the unpatched sshd will fail to start if KerberosUniqueCCache is set:

line 1: Bad configuration option: KerberosUniqueCCache

Would it make sense to have openssh-server-default-ccache install a config file, say:
  /etc/ssh/sshd_config.d/openssh-server-default.ccache.conf.disabled
That contains a commented out #KerberosUniqueCCache config (would aide discoverability),and then a symlink that allows the "Include /etc/ssh/sshd_config.d/*.conf" to pick it up:
    openssh-server-default.ccache.conf -> openssh-server-default-ccache.conf.disabled

The symlink would always be removed in uninstall, leaving any KerberosUniqueCCache setting impotent.

Also, do we need to restart sshd after an o-s-d-c install or removal?