Changing empty systematics test from test_commondataparser.py
Created by: siranipour
#807 added systematics for CMSWCHARMRAT
and now no other dataset suffers from the nsys=0
problem.
I think we should discourage having tests that rely on the number of datapoints/systematics in the future (imho).
Also, we should probably figure out a way to auto rebase whenever a new test gets added after a branching point