Revert "Include list of attached volumes with instance info"

This reverts commit dd66f235ecf2ff67819917ee07bcb0ea13a1b17b.

This changed the core servers API without doing it as an API extension,
so it's not an acceptable change as written.

Change-Id: I3787060583de1371e366647d38d69f37746317d5
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp