Fixed Hudson Conflict.

Redmine Hudson plugin does not work with Backlogs.

Redmine Hudson use jQuery 1.7.x it's default Redmine 2.1.x or later's library. But Backlogs override force it.

This request make backlogs use jquery 1.7.x when Redmine 2.1.x or later.
Before Remine 2.1.0, still uses backlogs's jquery.