tests - add haproxy cleanup for linux tests

examples/behind-reverse-proxy/cleanup-linux.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+if [ $(id -u) -ne 0 ] ; then
+	echo "❌ Run me as root"
+	exit 1
+fi
+
+systemctl stop haproxy

examples/proxy-protocol/cleanup-linux.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+if [ $(id -u) -ne 0 ] ; then
+	echo "❌ Run me as root"
+	exit 1
+fi
+
+systemctl stop haproxy