tests: PUBLICKEY_ACCEPTED_TYPES are effective

Verify the PUBLICKEY_ACCEPTED_TYPES option is handled correctly
and affects the signature algorithm selection based on the
extensions and can be used to limit list of offered mechanisms
to the server.

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
(cherry picked from commit 594c62d718)

src/pki.c

@@ -303,7 +303,7 @@ int ssh_key_algorithm_allowed(ssh_session session, const char *type)
  *
  * @return              A hash type to be used.
  */
-static enum ssh_digest_e ssh_key_type_to_hash(ssh_session session,
+enum ssh_digest_e ssh_key_type_to_hash(ssh_session session,
                                        enum ssh_keytypes_e type)
 {
     switch (type) {