FIX upload hints (#4357)

app/assets/javascripts/discourse/controllers/upload-selector.js.es6

@@ -20,7 +20,7 @@ export default Ember.Controller.extend(ModalFunctionality, {
     return allowsAttachments() ? "upload" : "picture-o";
   },
 
-  @computed('controller.local')
+  @computed('local')
   tip(local) {
     const source = local ? "local" : "remote";
     const authorized_extensions = authorizesAllExtensions() ? "" : `(${authorizedExtensions()})`;

app/assets/stylesheets/desktop/upload.scss

@@ -18,6 +18,7 @@
       }
       .description, .hint {
         color: dark-light-choose(scale-color($primary, $lightness: 50%), scale-color($secondary, $lightness: 50%));
+        display: block;
       }
       .hint {
         font-style: italic;