ci-test slot failures after gilab update

Gitlab was updated today and now we get an exception in ci-test build:

Traceback (most recent call last):
  File "/build/jenkins-tests/workspace/nightly-builds/main/venv/bin/lbn-enabled-slots", line 14, in <module>
    sys.exit(Script().run())
  File "/build/jenkins-tests/workspace/nightly-builds/main/venv/lib/python2.7/site-packages/LbCommon/Script.py", line 107, in run
    rc = self.main()
  File "/build/jenkins-tests/workspace/nightly-builds/main/venv/lib/python2.7/site-packages/LbNightlyTools/Scripts/EnabledSlots.py", line 140, in main
    ref_slot, mr_slot = make_mr_slots(mr_slots_config, slots)
  File "/build/jenkins-tests/workspace/nightly-builds/main/venv/lib/python2.7/site-packages/LbNightlyTools/MergeRequestBuilds.py", line 313, in make_mr_slots
    model_slots=model_slots)
  File "/build/jenkins-tests/workspace/nightly-builds/main/venv/lib/python2.7/site-packages/LbNightlyTools/MergeRequestBuilds.py", line 223, in create_mr_slots
    ref_date = mr_getrefdate(mrs.values())
  File "/build/jenkins-tests/workspace/nightly-builds/main/venv/lib/python2.7/site-packages/LbNightlyTools/MergeRequestBuilds.py", line 71, in mr_getrefdate
    "%Y-%m-%dT%H:%M:%S.%fZ"))
  File "/usr/lib64/python2.7/_strptime.py", line 325, in _strptime
    (data_string, format))
ValueError: time data '2020-01-29T15:38:19.000+00:00' does not match format '%Y-%m-%dT%H:%M:%S.%fZ'