Amend testpost.diff to use TLSv1.2 as a workaround for TLSv1.3 problems

Closes: #911938

debian/patches/testpost.diff

@@ -14,7 +14,7 @@ Author: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
  				   SSL_cert_file => "certs/server-cert.pem");
  
  ok($server, "made test server");
-@@ -43,7 +45,12 @@
+@@ -43,7 +45,13 @@
  unless (fork) {
      close($server);
  
@@ -22,6 +22,7 @@ Author: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
 +    my $mech = Test::WWW::Mechanize->new(
 +        ssl_opts => {
 +            SSL_verify_mode => IO::Socket::SSL::SSL_VERIFY_NONE,
++            SSL_version => 'TLSv1_2',
 +            verify_hostname => 0,
 +        }
 +    );