Commit 8e6d5474 ("sshd: use drop-in for basic sshd configuration")
changed the sshd_config.j2 template to contain only overridden bits of
sshd_config. However, it did not account for the install_arch role use
of the same template which was still installed to /etc/ssh/sshd_config.

Fix install_arch to install to etc/ssh/sshd_config.d/override.conf too.

Fixes: 8e6d5474 ("sshd: use drop-in for basic sshd configuration")