Add back default SSH algorithms for non-FIPS builds

!1315 (merged) fixed gitlab-sshd for FIPS hosts, but in inadvertently locked down SSH host key algorithms such as ssh-rsa. Restore these defaults until a proper deprecation path is set forward.

On the GDK, you can verify this via:

ssh -v -o "PubkeyAcceptedAlgorithms=ssh-rsa" git@localhost -p 2222

Changelog: fixed