Added forgotten shebang to postinst

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@1874 d4fa192b-c00b-0410-8231-f00ffab90ce4

debian/varnish.postinst

+#!/bin/sh
+
+
 # Automatically added by dh_installinit
 if [ -x "/etc/init.d/varnish" ]; then
 	update-rc.d varnish defaults >/dev/null