qa: fix 829 with a minor change to pcp-dmcache
qa: fix 829 with a minor change to pcp-dmcache

recent change to pmcc.py broke qa/829 because pcp-dmcache was
printing report header one iteration too late (was checking
manager.counter % 1 instead of manager.counter % 0).

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp