Use CSS to hide reply forms

We were using inline styles and passing local variables around, while
the rule we were following is very simple: it's only hidden if it's a
form to reply to a comment.

app/views/comments/_comment.html.erb

@@ -107,7 +107,6 @@
             <% if !valuation || can?(:comment_valuation, comment.commentable) %>
               <%= render "comments/form", { commentable: comment.commentable,
                                            parent_id: comment.id,
-                                           toggeable: true,
                                            valuation: valuation } %>
             <% end %>
           <% end %>