made the character count selected in new_thread_modal unique

app/views/comments/_new_thread_modal.html.erb

@@ -31,8 +31,8 @@
                         required: true,
                         data: { post: post.id,
                                 thread: '-1',
-                                character_count: ".js-character-count-#{post.id}" } %>
-      <%= render 'shared/char_count', type: post.id, min: min_chars, max: max_chars %>
+                                character_count: ".js-character-count-new-thread-#{post.id}" } %>
+      <%= render 'shared/char_count', type: "new-thread-#{post.id}", min: min_chars, max: max_chars %>
 
       <%= label_tag :title, 'Comment thread title (optional)', class: 'form-element' %>
       <span class="form-caption">