Fix Requests_ApproverVoteModel::findUsersVotesForRequests() to not bomb out...

Fix Requests_ApproverVoteModel::findUsersVotesForRequests() to not bomb out when given an empty array.

application/modules/requests/models/ApproverVoteModel.php

@@ -41,6 +41,9 @@ class Requests_ApproverVoteModel extends Unl_Model
         $select = new Zend_Db_Select($db);
         $select->from(array('a' => 'creqApproverVotes'), array('approverVoteId', 'request'));
         if (Unl_Util::isArray($requests)) {
+        	if (count($requests) == 0) {
+        		return new Unl_Model_Collection(__CLASS__);
+        	}
             $select->where('a.request IN(?)', $requests->getId());
         } else {
             $select->where('a.request = ?', $requests->getId());