Added the editor2 user to the test site.

tests/test_site/templates/login.html

@@ -29,6 +29,7 @@ First written: 2023/1/27
   <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
   <button class="btn btn-primary" type="submit" name="username" value="viewer">{{ _("Viewer") }}</button>
   <button class="btn btn-primary" type="submit" name="username" value="editor">{{ _("Editor") }}</button>
+  <button class="btn btn-primary" type="submit" name="username" value="editor2">{{ _("Editor2") }}</button>
   <button class="btn btn-primary" type="submit" name="username" value="nobody">{{ _("Nobody") }}</button>
 </form>