Remove targeted down voting report.

Remove the targeted down voting report. This report hasn't been working
for a while. The /post_votes page is a better way to investigate
downvoting activity anyway.

app/views/posts/partials/show/_options.html.erb

@@ -67,7 +67,6 @@
 
         <% if CurrentUser.is_moderator? %>
           <li id="post-option-replace-image"><%= link_to "Replace image", new_post_replacement_path(post_id: post.id), remote: true %></li>
-          <li id="post-option-down-vote-report"><%= link_to "Down vote report", reports_down_voting_post_path(post_id: post.id) %></li>
         <% end %>
       <% end %>
     <% end %>