add classic theme to user edit (#1409)

templates/site/user/edit.jet.html

@@ -55,6 +55,7 @@
       <option value="">{{ T("theme_select")}}</option>
       <option value="g"{{ if Theme == "g" }} selected{{end}}>/g/</option>
       <option value="tomorrow"{{ if Theme == "tomorrow" }} selected{{end}}>Tomorrow</option>
+      <option value="classic"{{ if Theme == "classic" }} selected{{end}}>Classic</option>
       <option value=""{{ if Theme == "" }} selected{{end}}>{{ T("theme_none")}}</option>
     </select>
     <br/>