Add warning if metadata_proxy_shared_secret is not configured
Add warning if metadata_proxy_shared_secret is not configured

Change-Id: I807028586737002533502b66fc4c37ac9dfb0476

mikalstill/nova,klmitch/nova,vmturbo/nova,jianghuaw/nova,vmturbo/nova,klmitch/nova,alaski/nova,gooddata/openstack-nova,Juniper/nova,rajalokan/nova,rajalokan/nova,hanlind/nova,rahulunair/nova,Juniper/nova,phenoxim/nova,gooddata/openstack-nova,hanlind/nova,hanlind/nova,rahulunair/nova,mahak/nova,phenoxim/nova,vmturbo/nova,rajalokan/nova,cloudbase/nova,openstack/nova,gooddata/openstack-nova,mahak/nova,Juniper/nova,rahulunair/nova,sebrandon1/nova,alaski/nova,cloudbase/nova,Juniper/nova,klmitch/nova,sebrandon1/nova,rajalokan/nova,jianghuaw/nova,jianghuaw/nova,sebrandon1/nova,mahak/nova,mikalstill/nova,openstack/nova,cloudbase/nova,vmturbo/nova,openstack/nova,klmitch/nova,jianghuaw/nova,gooddata/openstack-nova,mikalstill/nova