site: place 'search...' at the bottom of the search options (#7021) (#7022)

site/theme/template/Layout/Header.jsx

@@ -227,10 +227,10 @@ export default class Header extends React.Component {
                 onSearch={this.handleInputChange}
                 getPopupContainer={trigger => trigger.parentNode}
               >
+                {options}
                 <Option value={searchEngine} data-label={searchEngine}>
                   <FormattedMessage id="app.header.search" />
                 </Option>
-                {options}
               </Select>
             </div>
             {menuMode === 'horizontal' ? menu : null}