tests/acceptance: Enable AVOCADO_ALLOW_UNTRUSTED_CODE in the gitlab-CI

The tests are running in containers here, so it should be OK to
run with AVOCADO_ALLOW_UNTRUSTED_CODE enabled in this case.

Message-Id: <20201023073351.251332-4-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

.gitlab-ci.yml

@@ -66,6 +66,7 @@ include:
     - if [ -d ${CI_PROJECT_DIR}/avocado-cache ]; then
         du -chs ${CI_PROJECT_DIR}/avocado-cache ;
       fi
+    - export AVOCADO_ALLOW_UNTRUSTED_CODE=1
   after_script:
     - cd build
     - python3 -c 'import json; r = json.load(open("tests/results/latest/results.json")); [print(t["logfile"]) for t in r["tests"] if t["status"] not in ("PASS", "SKIP", "CANCEL")]' | xargs cat