send-email: provide port separately from hostname

If the SMTP port is provided as part of the hostname to Net::SMTP, it passes
the combined string to the SASL provider; this causes GSSAPI authentication to
fail since Kerberos does not want the port information.  Instead, pass the port
as a separate argument as is done for SSL connections.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-send-email.perl

@@ -1199,9 +1199,11 @@ sub send_message {
 		else {
 			require Net::SMTP;
 			$smtp_domain ||= maildomain();
-			$smtp ||= Net::SMTP->new(smtp_host_string(),
+			$smtp_server_port ||= 25;
+			$smtp ||= Net::SMTP->new($smtp_server,
 						 Hello => $smtp_domain,
-						 Debug => $debug_net_smtp);
+						 Debug => $debug_net_smtp,
+						 Port => $smtp_server_port);
 			if ($smtp_encryption eq 'tls' && $smtp) {
 				require Net::SMTP::SSL;
 				$smtp->command('STARTTLS');