gstlal_cs_triggergen raises TabError on python3

The gstlal_cs_triggergen script from gstlal-burst results in a TabError when running on python3:

+ gstlal_cs_triggergen --help
  File "/home/duncan/opt/miniconda3/conda-bld/gstlal-burst_1612355711012/_test_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/bin/gstlal_cs_triggergen", line 63
    parser.add_option("--channel", metavar = "channel", action = "append", type = "string", help = "Name of channel. Can be given multiple inputs, but must be one for each detector.")
                                                                                                                                                                                      ^
TabError: inconsistent use of tabs and spaces in indentation