use checkbox for compact layout

src/components/views/settings/tabs/user/AppearanceUserSettingsTab.tsx

@@ -273,7 +273,7 @@ export default class AppearanceUserSettingsTab extends React.Component<IProps, I
                     })}
                 </div>
                 {customThemeForm}
-                <SettingsFlag name="useCompactLayout" level={SettingLevel.ACCOUNT} />
+                <SettingsFlag name="useCompactLayout" level={SettingLevel.ACCOUNT} useCheckbox={true} />
            </div>
         );
     }