Amend wrapper_funpack to match README
Presently generate_inital_data/README.md directs the user to set env var NONIDPDATA with a path to UKB csv files with tabular data. However, there are no references to $NONIDPDATA anywhere in the code, yet there is a $input1 in wrapper_funpack.sh that is asking to be set to what is $NONIDPDATA.
This impliments that change.