packaging: setup: Quote values in /etc/sysconfig/nfs

Quote values in variable assignments in /etc/sysconfig/nfs.
Unquoted values might break sysvinit-based nfs init sh scripts.

Bug-Url: https://bugzilla.redhat.com/1013347
Change-Id: Ie62b0f47b0244434967e9af13fcde7614280825b
Signed-off-by: Yedidyah Bar David <didi@redhat.com>