bug fixed: was trying to remove an unexisting span.votes

The bug was invisible to the user but if you opened a web console you could see a JS error.
You can reproduce this bug on the demo page by:
1) writing a new comment
2) trying to upvote or downvote your comment
What happened then was:
1) Not changing anything to the vote count (that's OK you can't upvote or downvote your own comments).
2) Triggering a new JS error: TypeError: n is null