CRM-13710 fix - Required prices sets still required even when not active

Issue was occurring because the priceset form element which we are assigning to template is not the same on which the formRule is performing validation instead using $form->_values['fee'] which I found that it contains the DAO object values of the priceset used where in-activeness check is not performed unlike $priceSet = self::getSetDetail($priceSetId, TRUE, $validFieldsOnly) which we are currently using. My changes is syncing the two variables to act like one.