vdsm.spec: Require openssl

deployUtil uses openssl command, we should Require it.

Change-Id: Ib53aa66bad94e9c4046f3430b892a60cbc80c520
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=905728
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/11527
Reviewed-by: Fabian Deutsch <fabiand@fedoraproject.org>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>