fix(cgi-bin): handle VMs without VNC port in get_vnc_info

cgi-bin/manage_vnc_ports

@@ -72,18 +72,21 @@ sub get_vnc_info
 	my $shell_call  = "ssh root@".$host_name." \"virsh vncdisplay ".$server_name."\"";
 
 	my ($shell_output, $shell_return_code) = $anvil->System->call({ shell_call => $shell_call });
-	my ($port_offset)                      = $shell_output =~ /:(\d+)$/;
-	my $port_sum                           = $port_base + int($port_offset);
+
 	$anvil->Log->variables({ source => $THIS_FILE, line => __LINE__, level => 2, list => {
 		shell_output      => $shell_output,
-		shell_return_code => $shell_return_code,
-		port_offset       => $port_offset,
-		port_sum          => $port_sum
+		shell_return_code => $shell_return_code
 	} });
 
 	if ($shell_return_code == 0)
 	{
-		$vnc_info->{port} = $port_sum;
+		my ($port_offset) = $shell_output =~ /:(\d+)$/;
+		$vnc_info->{port} = $port_base + int($port_offset);
+
+		$anvil->Log->variables({ source => $THIS_FILE, line => __LINE__, level => 2, list => {
+			port_offset => $port_offset,
+			vnc_port    => $vnc_info->{port}
+		} });
 	}
 
 	return $vnc_info;