Do not call set -x in an environment (element) file

See https://review.openstack.org/#/c/388972/ for details.

Also, do no enable other settings which are most likely
not useful in a environment file.

Change-Id: Id36ad00295725fa60b55713fb706555789fd3a78

elements/hdp-local-mirror/environment.d/99-set-up-default-apache-dir

@@ -1,11 +1,3 @@
-#!/bin/bash
-
-if [ "${DIB_DEBUG_TRACE:-0}" -gt 0 ]; then
-    set -x
-fi
-set -eu
-set -o pipefail
-
 case "${DISTRO_NAME}" in
     centos | centos7 | rhel | rhel7 | fedora )
         export DIB_DEFAULT_APACHE_DIR="/var/www/html"