Fix for https://trello.com/c/8NpgYM3U/1430-tool-panel-label-bug-introduced-with-2014-02-10

Bug was introduced in commit 5f6c670dca9f42d52480f66afeb91b63710e7ffb .
Merged in nsoranzo/galaxy-central (pull request #346)

Fix for https://trello.com/c/8NpgYM3U/1430-tool-panel-label-bug-introduced-with-2014-02-10