Update to v1.20.1

The nightly build has just been updated to v1.20.1. This fixes a minor bug introduced in the Load text-based files and PDB Loader nodes in v1.20.0, which means that the removed input column names is not de-dupicated in the output table (e.g. ‘File’ as input column would be rendered ‘File(#1)’ in the out table, even when the new ‘Remove input column’ option was checked)