Unset UPPER_CONSTRAINTS_FILE on dib
After setting the UPPER_CONSTRAINTS_FILE, gates started failing
because of side effects, as this var was being taken as part of
the image build. Unset it after requirements have been installed
and before actually running the tests.
# which are used during test runs
./openstack/diskimage-builder/contrib/setup-gate-mirrors.sh
+ # UPPER_CONSTRAINTS_FILE is causing side effects when doing image
+ # build, unset it
+ unset UPPER_CONSTRAINTS_FILE
+
# activate the virtualenv so that any tools run by dib run
# using the python inside it
set +u
