biscuit module KeyError

[efratushava]

Description of bug:
My command failes, and the error massage instructed me to report an issue...

MultiQC Error log:

[ERROR  ]         multiqc : Oops! The 'biscuit' MultiQC module broke...
  Please copy the following traceback and report it at https://github.com/ewels/MultiQC/issues
  If possible, please include a log file that triggers the error - the last file found was:
    ./biscuit_QC/File_biscuitQC/File_covdist_q40_botgc_table.txt
[File_covdist_q40_botgc_table.txt](https://github.com/ewels/MultiQC/files/4159241/File_covdist_q40_botgc_table.txt)

============================================================
Module biscuit raised an exception: Traceback (most recent call last):
  File "lib/python2.7/site-packages/multiqc/multiqc.py", line 546, in run
    output = mod()
  File "lib/python2.7/site-packages/multiqc/modules/biscuit/biscuit.py", line 113, in __init__
    getattr(self, 'chart_{}'.format(k))()
  File "lib/python2.7/site-packages/multiqc/modules/biscuit/biscuit.py", line 740, in chart_retention_cpg_readpos
    dict([(k,v['1']) for k, v in self.mdata['retention_cph_readpos'].items()]),
KeyError: '1'
============================================================

File that triggers the error:
File_covdist_q40_botgc_table.txt

MultiQC run details (please complete the following):

• Command used to run MultiQC: multiqc -f --config multiqc_config.yaml . -m fastqc -m biscuit

• MultiQC Version: multiqc, version 1.8

• Operating System: Debian- Kernel Linux 4.4.146-aufs-1

• Python Version: Python 2.7.15

• Method of MultiQC installation: tried with pip or conda,( conda was through docker/singularity)

Additional context
Add any other context about the problem here.