engine: Allow using vnic profiles internally

When action is being executed internally, there is no
user associated with the action, and the action should
be treated as executed by the admin. In that case, there
is no need to search for a permissions on a vnic profile
to be used by the user.

Change-Id: I7665d5d53519cdb2560ae2aed0b02c4229c80964
Bug-Url: https://bugzilla.redhat.com/1018229
Signed-off-by: Moti Asayag <masayag@redhat.com>