Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1123685
Steps to Reproduce:
1. create compute resource on rhev with a blank quota
2. provision a host on that compute resource

Actual results:
Provisioning fails with "Failed to create a compute" "Internal Engine Error"

Expected results:
Provisioning succeeds

Additional info:

RHEV 3.4.1-0.30.el6ev

Additional debugging pointed to the quota parameter not being accepted, when set to "", switching to nil seemed to fix the issue