Merge pull request #146 from misakichan/patch-2

解决菜单展开时dialog高度太高，无法显示确认和取消按钮的问题

Author: wenjianzhang

src/views/admin/sys-role/index.vue

@@ -194,6 +194,7 @@
                 show-checkbox
                 node-key="id"
                 :empty-text="menuOptionsAlert"
+                style="height:171px;overflow-y:auto;overflow-x:hidden;"
               />
             </el-form-item>
             <el-form-item label="备注">