Added SEM_VT to varnish param blacklist.
Added SEM_VT to varnish param blacklist.

kkwoker/ansible-varnish,noqcks/ansible-varnish,gotofbi/ansible-varnish,killerwails/ansible-varnish,colstrom/ansible-varnish,telusdigital/ansible-varnish,killerwails/ansible-varnish,gotofbi/ansible-varnish