MS raw data conversion ETL script references unused json file

[wow-such-code]

The json meta data file is currently not used - was ist ever? -, we should decide if we want to remove it here or if we want to reintroduce it.

[wow-such-code]

https://github.com/qbicsoftware/etl-scripts/blob/master/drop-boxes/register-convert-ms-vendor-format/etl_msconvert.py#L292