Patch for vr_campaign_nodeapi: Recreate campaign which has been deleted in VR

Just a patch for the following "TODO":

function vr_campaign_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
[...]
case 'update':
//TODO: It is possible that the campaign has been deleted in VerticalResponse
// we need to confirm that it exists, and recreate it if it does not.