engine: Block Hot Adding a Nic in 3.0

This patch makes sure not to hot-plug a nic in a
VM that belongs to a cluster with a version that
does not support hot-plugging. Previously, the
condition that was used in the canDoAction coupled
between two conditions that are not related.

Change-Id: Ic0ee6563b55a84421b3a9a068e6d69ff228d46ae
Bug-Url: https://bugzilla.redhat.com/923332
Signed-off-by: Muli Salem <msalem@redhat.com>