Unify `-x' shell attribute in cartridge scripts

Turn off debugging level output:
- `set +x' by default
- `set -x' should be enabled explicitely for debugging purposes only

Bug 1168512 - https://bugzilla.redhat.com/show_bug.cgi?id=1168512
Merge pull request #5989 from VojtechVitek/bug_1168512

Merged by openshift-bot