summarypages with `--compare_results` failure

@serguei.ossokine found the following error when running the command line:

$ summarypages -w /home/serguei.ossokine/public_html/LVC/O3a/S190408an/comparison_preferred -s posterior_samples.h5  --no_ligo_skymap --gw --multi_process 6  --publication --compare_results C01:IMRPhenomPv2

output:

Traceback (most recent call last):
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/bin/summarypages", line 8, in <module>
    sys.exit(main())
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/lib/python3.7/site-packages/pesummary/cli/summarypages.py", line 206, in main
    args = func["input"](opts)
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/lib/python3.7/site-packages/pesummary/gw/inputs.py", line 694, in __init__
    "waveform_fits"
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/lib/python3.7/site-packages/pesummary/core/inputs.py", line 1228, in __init__
    self.samples = self.opts.samples
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/lib/python3.7/site-packages/pesummary/core/inputs.py", line 444, in samples
    self._set_samples(samples)
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/lib/python3.7/site-packages/pesummary/core/inputs.py", line 467, in _set_samples
    i, self.labels[num], config=None, injection=None
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/lib/python3.7/site-packages/pesummary/core/inputs.py", line 761, in grab_data_from_input
    **grab_data_kwargs
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/lib/python3.7/site-packages/pesummary/gw/inputs.py", line 46, in grab_data_from_metafile
    **kwargs
  File "/nfshome/store04/users/serguei.ossokine/envs/postproc/lib/python3.7/site-packages/pesummary/core/inputs.py", line 116, in grab_data_from_metafile
    for param in DataFrame[label].keys():
KeyError: 'C01:IMRPhenomD'