Fix py26 timeouts
Fix py26 timeouts

tests.benchmark.test_runner.test_run_scenario_exception_inside_test
sometimes produce gate timeouts (worked more then 60 minutes)

Seems like the issues was related to the way we use mock.

Change-Id: I96c79b4d6d321931015413e7a308ddd3d1d83f20
Closes-Bug: #1271831

gluke77/rally,gluke77/rally,aforalee/RRally,cernops/rally,openstack/rally,cernops/rally,afaheem88/rally,aplanas/rally,ytsarev/rally,pandeyop/rally,amit0701/rally,openstack/rally,eayunstack/rally,redhat-openstack/rally,vefimova/rally,redhat-openstack/rally,gluke77/rally,vganapath/rally,vganapath/rally,pyKun/rally,vganapath/rally,varunarya10/rally,aforalee/RRally,amit0701/rally,ytsarev/rally,eonpatapon/rally,go-bears/rally,group-policy/rally,group-policy/rally,varunarya10/rally,vganapath/rally,openstack/rally,pandeyop/rally,vponomaryov/rally,vefimova/rally,pyKun/rally,go-bears/rally,afaheem88/rally,paboldin/rally,openstack/rally,group-policy/rally,aplanas/rally,amit0701/rally,eayunstack/rally,yeming233/rally,shdowofdeath/rally,paboldin/rally,gluke77/rally,eayunstack/rally,shdowofdeath/rally,yeming233/rally,paboldin/rally,eonpatapon/rally,vponomaryov/rally