PESummary unable to handle Bilby-MCMC

When running summarypages on a Bilby-MCMC and analysis, this line errors out with a KeyValueError on the maxL. It seems that grab_key_data_from_results_files() ends up with a big dictionary of None's rather than a dictionary of dictionaries as it expects.

You can find an example result file here CIT:/home/gregory.ashton/public_html/bilby_review/bilby1.1.5-88cf7e2-CLEAN_bilby_pipe1.0.4-a0f8deb-CLEAN/bilby_o4_review/GW150914/outdir_bilbymcmc_A/final_result/ProdF4_data0_1126259462-391_analysis_H1L1_bilby_mcmc_merge_result.json