deployUtil: expect integer vlan id from new netinfo

Commit 8b2bbe6e5 changed netinfo.getVlanID() to return the vlan id as an
integer, istead of a string. This makes a lot of sense, but breaks
compatibility with ancient deployUtil code.

Change-Id: Ibc1c5875e0d13b110f61f9eabf6d1964fc4c1237
Bug-Url: https://bugzilla.redhat.com/1037277
Signed-off-by: Dan Kenigsberg <danken@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/21948
Reviewed-by: Amador Pahim <apahim@redhat.com>
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>