sshserver: remove use of AuthorizedKeysFile2

Support for the (undocumented) AuthorizedKeysFile2 was removed in
OpenSSH 5.9, released in September 2011

Closes #715

tests/sshserver.pl

@@ -6,7 +6,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -409,7 +409,6 @@ if ($^O eq 'MSWin32' || $^O eq 'cygwin' || $^O eq 'msys') {
 #  AllowTcpForwarding               : OpenSSH 2.3.0 and later
 #  AllowUsers                       : OpenSSH 1.2.1 and later
 #  AuthorizedKeysFile               : OpenSSH 2.9.9 and later
-#  AuthorizedKeysFile2              : OpenSSH 2.9.9 and later
 #  Banner                           : OpenSSH 2.5.0 and later
 #  ChallengeResponseAuthentication  : OpenSSH 2.5.0 and later
 #  Ciphers                          : OpenSSH 2.1.0 and later [3]
@@ -498,7 +497,6 @@ push @cfgarr, 'DenyGroups';
 push @cfgarr, 'AllowGroups';
 push @cfgarr, '#';
 push @cfgarr, "AuthorizedKeysFile $clipubkeyf_config";
-push @cfgarr, "AuthorizedKeysFile2 $clipubkeyf_config";
 push @cfgarr, "HostKey $hstprvkeyf_config";
 push @cfgarr, "PidFile $pidfile_config";
 push @cfgarr, '#';