[theme] add newline at the end of the file

searx/templates/simple/simple_search.html

@@ -6,4 +6,4 @@
       <button id="send_search" type="submit" tabindex="-1"><span class="hide_if_nojs">{{ icon('search') }}</span><span class="show_if_nojs">{{ _('Start search') }}</span></button>
     </div>
   </div>
-</form>
+</form>