Delete meaningless lines in test_server_metadata.py

Some meaningless lines were found in test_server_metadata.py.
I deleted those.

Change-Id: I3f04bc0d4c9048281293ed78e4ba7ea4a2b26864
Don't import library guestfs directly

Library guestfs is not in requirements file, but is imported directly
in nova/virt/disk/vfs/guestfs.py. That conflicts with global variable
guestfs, leads out one more time import and shadow issue, so remove it
from import group.

Closes-Bug: #1293298

Change-Id: I55530ed682ebf449673759ab6127bcd28cb92594
Merge "Delete meaningless lines in test_server_metadata.py"
Merge "Don't import library guestfs directly"