Remove require_admin_context
Remove require_admin_context

this function was used to put into db layer to ensure
the request has admin context or a unauthorized exception
will be raised, this is not needed as we already move
all this kind of check into api layer and policy functions.

Change-Id: Ia411e6715e4c584952a275a001f1791ca1352d97

rahulunair/nova,rajalokan/nova,jianghuaw/nova,vmturbo/nova,rahulunair/nova,hanlind/nova,openstack/nova,Juniper/nova,hanlind/nova,mikalstill/nova,rajalokan/nova,klmitch/nova,rahulunair/nova,klmitch/nova,vmturbo/nova,rajalokan/nova,klmitch/nova,hanlind/nova,klmitch/nova,gooddata/openstack-nova,Juniper/nova,gooddata/openstack-nova,mahak/nova,phenoxim/nova,gooddata/openstack-nova,jianghuaw/nova,jianghuaw/nova,phenoxim/nova,mahak/nova,mahak/nova,mikalstill/nova,jianghuaw/nova,openstack/nova,vmturbo/nova,openstack/nova,vmturbo/nova,Juniper/nova,mikalstill/nova,gooddata/openstack-nova,rajalokan/nova,Juniper/nova