管理人员角色相关优化

src/pages/system/administrator/index.tsx

@@ -200,6 +200,7 @@ const SystemAdministratorPage = () => {
           </div>
           <div className="float-left j-b-flex mb-24">
             <div className="d-flex">
+              {role_ids.length === 0 && (
                 <PerButton
                   text="新建角色"
                   icon={<PlusOutlined />}
@@ -209,6 +210,7 @@ const SystemAdministratorPage = () => {
                   onClick={() => setCreateRoleVisible(true)}
                   disabled={null}
                 />
+              )}
               <PerButton
                 type="default"
                 text="添加管理员"