Support force update quota

Once we have additional check when update quota in
https://review.openstack.org/#/c/25887/, we need provide --force option
when run 'nova quota-update'.

Since the change in nova server has been merged, we need re-enable the
changes in nova client side.

Fix bug 1160749

Change-Id: Iceb67c5816312fafed8a68e48a8a136c03d0bb5b
Merge "Support force update quota"