Fix bug in Data_Source when update item errors occurs

SE/se-lib/Data_Source.php

@@ -785,7 +785,7 @@ if(V::get('DBG_DS', 0, $_GET) > 2){echo'<pre style="max-height:200px;overflow:au
 		$itemPatch = (object)$itemPatch;
 		$affected = $this->_db->UPDATE_OBJ($this->_tbl, $itemPatch);
 		if ($affected < 0) {
-			$dsErrors = $ds->getDbErrors();
+			$dsErrors = $this->getDbErrors();
 			$dsErrors = "Wystąpiły błędy!\n" . implode("\n", $dsErrors);
 			throw new Exception($dsErrors);
 		}