Fix PHP5.4 compatibility

library/Class/CustomField/ModelValues.php

@@ -90,7 +90,8 @@ class Class_CustomField_ModelValues {
 	public function save() {
 		$values = $this->getFieldValues();
 		foreach($values as $value) {
-			empty($value->getValue()) ? $value->delete() : $value->save();
+			$inner_value = $value->getValue();
+			empty($inner_value) ? $value->delete() : $value->save();
 		}
 		return $this;
 	}