Fix request_disk and request_memory for lensingflow
Due to the change in units handling for request_disk and request_memory in Bilby, it seems like the interpolator generator submit file had an issue, i.e. it did not add the units as is done in bilby, leading to the request being done in bytes and the runs getting hold. This is fixed by checking the presence of units in the request and adding them if necessary.
- small fix in a docstring.