si_create_rollup_vars.sas - Rollup doesnt work if no si_aggs_cols is chosen

[Wen Jhe Lee]

si_create_rollup_vars.sas : parameter si_aggs_cols needs to = department. This doesnt work if there is no roll up chosen. i.e if we want to just roll up by snz_uid

for example if we choose si_aggs_cols=%str(snz_uid) , this would fail.

Might need to re code this?