only show comment downvote summary if its total score is <= 0

when a comment has a few upvotes and one downvote, users tend to
focus too much on the one downvote and edit or reply and debate the
downvote.  if more upvoted than downvoted, don't discourage the user
by pointing out the haters

app/views/comments/_comment.html.erb

@@ -71,7 +71,8 @@ class="comment <%= comment.current_vote ? (comment.current_vote[:vote] == 1 ?
        <% end %>

        <span class="reason">
          <% if comment.downvotes > 0 && comment.user_id == @user.try(:id) %>
          <% if comment.downvotes > 0 && comment.score <= 0 &&
          comment.user_id == @user.try(:id) %>
            | <%= comment.vote_summary.downcase %>
          <% elsif comment.current_vote && comment.current_vote[:vote] == -1 %>
            | <%= Vote::COMMENT_REASONS[comment.current_vote[:reason]].downcase