[FIX] web: FieldMany2Many: don't save if nothing changed

Suppose that there is a many2many list (non editable) in a form
view. When one of the many2many subrecords is edited (from the
form view in a dialog), it is saved directly when the user clicks
on 'Save' in the dialog.

Before this rev., if the user clicked on 'Save' in the main form
view after editing a m2m subrecord, a 'write' RPC was done, whereas
there were nothing left to save (as the subrecord had already been
saved).

0 files changed, 0 insertions, 0 deletions