Before this revision, the `char_domain` re-rendered its display
only when its domain value was changed.
It must re-render as well when the model on which this domain
is applied is changed, as the number of records can
obviously be different.
e.g., in mass-mailing, when changing the recipients type
from partners to leads, the domain doesn't change, it
stays `['opt_out', '=', False]`, but the model on which
this domain is applied does change, as well as the number
of selected records.
opw-658391
2939800ed4