(hot fix) fixes broken 'add' button introduced in I14e89ecc

Will probably require Ia6a7ee90 for nice disabling during save. Can be merged before though, since
the call to jQuery.Widget.option() will always work.

Change-Id: Ia779c93bb18fdac763ce569ecc3286ab932f5043
Merge "(hot fix) fixes broken 'add' button introduced in I14e89ecc"