ATR-19820: adding 'athenaHLT.py: error' to error patterns.
Following the discussion in ATR-19820:
adding "athenaHLT.py: error" as error pattern for CheckLog, catching failures as in https://atlas-art-data.web.cern.ch/atlas-art-data/build-output/master/Athena/x86_64-centos7-gcc8-opt/2019-06-03T2126/TrigP1Test/test_HelloWorldHLT_run_stop_run_build/