Make the check for numa=off optional for CentOS 6.6+, and http_caching=packages optional for CentOS, in case BVT-VERIFY-VHD-PREREQUISITES.
Make the check for numa=off optional for CentOS 6.6+, and http_caching=packages optional for CentOS, in case BVT-VERIFY-VHD-PREREQUISITES.

hglkrijger/azure-linux-automation,FreeBSDonHyper-V/azure-freebsd-automation,Nidylei/azure-linux-automation,FreeBSDonHyper-V/azure-freebsd-automation,iamshital/azure-linux-automation,v-sirebb/azure-linux-automation,FreeBSDonHyper-V/azure-freebsd-automation,iamshital/azure-linux-automation,v-sirebb/azure-linux-automation,konkasoftci/azure-linux-automation,Nidylei/azure-linux-automation,hglkrijger/azure-linux-automation,konkasoftci/azure-linux-automation,iamshital/azure-linux-automation,Nidylei/azure-linux-automation,v-sirebb/azure-linux-automation,hglkrijger/azure-linux-automation,konkasoftci/azure-linux-automation