Merge fix from upstream to really disable MQTT.

net/gnugk/patches/patch-configure

@@ -1,4 +1,10 @@
-$OpenBSD: patch-configure,v 1.27 2020/01/25 05:55:20 ajacoutot Exp $
+$OpenBSD: patch-configure,v 1.28 2020/04/20 21:37:40 ajacoutot Exp $
+
+Last chunks:
+From e303b7cde99528382d8b06dcec4e50791ca59342 Mon Sep 17 00:00:00 2001
+From: Jan Willamowius <jan@willamowius.de>
+Date: Mon, 3 Feb 2020 14:34:55 +0100
+Subject: [PATCH] fix configure switch to disable MQTT and AMQP
 
 Index: configure
 --- configure.orig
@@ -12,3 +18,21 @@ Index: configure
  if test "${PTLIBSNMPSUPPORT:-unset}" = "unset" ; then
  	if test "x${ptlibsnmp}" != "xno" ; then
  		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: No PTLib SNMP support available" >&5
+@@ -5986,6 +5986,8 @@ fi
+ 
+ done
+ 
++else
++   HAS_LIBMOSQUITTO=0
+ fi
+ 
+ if test "x${HAS_LIBMOSQUITTO}" != "x0" ; then
+@@ -6026,6 +6028,8 @@ fi
+ 
+ done
+ 
++else
++   HAS_LIBRABBITMQ=0
+ fi
+ 
+ if test "x${HAS_LIBRABBITMQ}" != "x0" ; then