Remove obsolete glossary entry Volume Service API
Remove obsolete glossary entry Volume Service API

This entry has been obsoleted, remove it.

Change-Id: I2faf22eec0784bb403817d96b50ec8921b778593

saeki-masaki/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,potsmaster/openstack-manuals,kairoaraujo/openstack-manuals,openstack/openstack-manuals,Akasurde/openstack-manuals,gongysh2004/openstack-manual,Akasurde/openstack-manuals,saeki-masaki/openstack-manuals,kairoaraujo/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,gongysh2004/openstack-manual,AlekhyaMallina-Vedams/openstack-manuals,potsmaster/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals