re-store for GEN relvals the EnableHarvesting reqmgr parameter and set harvesting as no-step; this had gotten lost between 62x and now. This change does not affect IB/local tests
Merge pull request #5586 from franzoni/swapt-gen-ext-CMSSW_7_2_0_pre6

re-store for GEN relvals the EnableHarvesting in reqmgr