Bug#774711: openssh-server: insecure algorithms reported by ssh-audit

Thanks for the ssh-audit report output!
There has been a very long discussion of default settings in #774711 
(which now includes ssh-audit's recommendations)

Since you generated this report the following has happened:

* 1:8.8p1-1:
   "This release disables RSA signatures using the SHA-1 hash algorithm
    by default.  (Existing RSA keys may still be used and do not need
    to be replaced; see NEWS.Debian if you have problems connecting to
    old SSH servers.)"
* 1:8.9p1-1:
   "ssh(1): stricter UpdateHostkey signature verification logic on the
    client-side. Require RSA/SHA2 signatures for RSA hostkeys except when
    RSA/SHA1 was explicitly negotiated during initial KEX.
    ssh(1), sshd(8): fix signature algorithm selection logic for
    UpdateHostkeys on the server side. The previous code tried to prefer
    RSA/SHA2 for hostkey proofs of RSA keys, but missed some cases. This
    will use RSA/SHA2 signatures for RSA keys if the client proposed
    these algorithms in initial KEX."
* 1:9.0p1-1:
   "use the hybrid Streamlined NTRU Prime + x25519 key exchange method
    by default ("[email protected]"). The NTRU algorithm
    is believed to resist attacks enabled by future quantum computers and
    is paired with the X25519 ECDH key exchange (the previous default) as
    a backstop against any weaknesses in NTRU Prime that may be
    discovered in the future. The combination ensures that the hybrid
    exchange offers at least as good security as the status quo."
* [email protected] is the defaults lists now

The rest of ssh-audit's recommendations from your report are still 
valid, see #774711 for more info