fix bug lp:980892,update glance doc.
fix bug lp:980892,update glance doc.

Change-Id: I5b231421be4dbb38a3af45783543bef50b74c09c

redhat-openstack/glance,cloudbau/glance,JioCloud/glance,openstack/glance,dims/glance,rajalokan/glance,klmitch/glance,wkoathp/glance,kfwang/Glance-OVA-OVF,saeki-masaki/glance,paramite/glance,darren-wang/gl,redhat-openstack/glance,SUSE-Cloud/glance,jumpstarter-io/glance,wkoathp/glance,citrix-openstack-build/glance,rickerc/glance_audit,rajalokan/glance,vuntz/glance,ntt-sic/glance,akash1808/glance,rickerc/glance_audit,stevelle/glance,openstack/glance,saeki-masaki/glance,kfwang/Glance-OVA-OVF,tanglei528/glance,scripnichenko/glance,dims/glance,paramite/glance,darren-wang/gl,sigmavirus24/glance,takeshineshiro/glance,openstack/glance,takeshineshiro/glance,akash1808/glance,klmitch/glance,vuntz/glance,ntt-sic/glance,scripnichenko/glance,cloudbau/glance,ozamiatin/glance,citrix-openstack-build/glance,JioCloud/glance,ozamiatin/glance,SUSE-Cloud/glance,stevelle/glance,tanglei528/glance,sigmavirus24/glance,jumpstarter-io/glance