Different output of Allen.mdf_input test

After merging !936 (merged) a strange behaviour of Allen.mdf_input was observed. This test is currently failing in master, however different tests are showing a different pattern.

Expected behaviour is Missing : gather_selections , for example at master-1746, master-1748, at unrelated MR master-mr-5152

However some tests are showing different behaviour, such as Counters in stdout and not in ref : ['Hlt1DiMuonSoftPass', 'Hlt1DiMuonSoftRate', 'Hlt1LowMassNoipDielectron_SS_massSlice3_displacedPass', 'Hlt1LowMassNoipDielectron_SS_massSlice3_displacedRate']

This was observed for example at: master-1745, tests at unrelated MR: master-mr-5175, master-mr-5171