beam_PostCommit_Python_Verify failure

[Chamikara Jayalath]

Seems like beam_PostCommit_Python_Verify has been consistently failing for
two days:
https://builds.apache.org/view/A-D/view/Beam/view/PostCommit/job/beam_PostCommit_Python_Verify/

Filed https://issues.apache.org/jira/browse/BEAM-7063

Thanks,
Cham