add some missing “set -ue” declarations

Since 79ab95b16e78d563c473b5acada62cb3e22d4eb1 dib-lint ensure
every element shell scripts have “set -e” activated.

Even if dib-lint doesn't test it yet, the set -u is already widely
used.

As pointed out by Jiri Stransky, elements/tripleo-cd/configs/* files
are sourced by deploy-testenv. There is no reason to enable “set -ue”
manually. The patch just disable the dib-lint “sete” check on these files.

Change-Id: I118c8c80ec50b265c22577b075d15f56389b7a47
Merge "add some missing “set -ue” declarations"