asterisk11-gui: remove postinst leftovers

Signed-off-by: Jiri Slachta <slachta@cesnet.cz>

admin/asterisk11-gui/files/agui-postinst

-#!/bin/sh
-
-CFG_PATH="/etc/asterisk/"
-GUI_CFG_PREFIX="gui_"
-CFG_FILES="http.conf manager.conf users.conf"
-
-for i in $CFG_FILES; do
-	if [ -f $CFG_PATH$i ]; then
-		mv $CFG_PATH$i $CFG_PATH$i".backup"
-	fi
-	cp $CFG_PATH$GUI_CFG_PREFIX$i $CFG_PATH$i
-done