simplified rule execution [skip ci]

framework/rbac/Manager.php

@@ -151,16 +151,12 @@ abstract class Manager extends Component
      */
     public function executeRule($ruleName, $params, $data)
     {
-        if ($ruleName !== null) {
         $rule = $this->getRule($ruleName);
         if ($rule instanceof Rule) {
             return $rule->execute($params, $data);
         } else {
             throw new InvalidConfigException("Rule not found: $ruleName");
         }
-        } else {
-            return true;
-        }
     }
 
     /**