JS: no need to set/reset accessible flag at each row access in PropertyBox
JS: no need to set/reset accessible flag at each row access in PropertyBox

There's no penalty to just creating all of our Field references as
accessible in the first place as these are only used internally within
PropertyBox.

Signed-off-by: Harvey Harrison <eadbd6b462bf3c97df0300a934c12bc2e5d1fe51@gmail.com>

jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim