try fixing post retry

contrib/templates/default/post_retry.mustache

@@ -14,6 +14,7 @@
     <input type="hidden" name="name" value="{{name}}" />
     <input type="hidden" name="subject" value="{{subject}}" />
     <input type="hidden" name="captcha_id" value="{{captcha_id}}" />
+    <input type="hidden" name="message" value="{{message}}" />
     <div id="postform-outer">
       <div id="postform-inner">
         <div>{{fail_message}}</div>