upload: fix template, show errors again

dist/templates/upload/upload.html.hbs

@@ -1,7 +1,12 @@
 {{#> layout }}
+  {{#with page}}
 <div class="ui">
   <center><h2>{{ text "Upload your key" }}</h2></center>
 
+  {{#with error }}
+    <p><strong>Error</strong>: {{ this }}</p>
+  {{/with}}
+
   <form action="/upload/submit" method="POST" enctype="multipart/form-data">
     <div class="upload">
       <input type="file" id="keytext" name="keytext" autofocus class="fileUpload" placeholder="{{ text "Your public key" }}"/>
@@ -17,4 +22,5 @@
 
   <script src="/assets/js/upload.js" async></script>
 </div>
+  {{/with}}
 {{/layout}}