fixes jstree ordering problem with jquery 1.9

Using Chrome browser i see a wrong taxons ordering on the taxon edit tree, using spree 1.3.2/1-3-stable (jquery-rails 2.2.x). No problems with spree 1.3.1 (jquery 2.1.x).
No problems with Firefox.

The jstree problem with jquery 1.9 was reported here: vakata/jstree#334 and the patch works.