This commit fixes a js crash that occured when the user was trying to
edit a new record while the chatter was not completely loaded
(this.field.thread.$el was not in the dom yet)
Behavior before this fix:
Traceback js & impossible to edit the form afterward.
Behavior after this fix:
no traceback, still possible to edit the form normally.
The thread will display on next chatter re-render. Could be forced by
triggering an onchange.
opw-1986061
closesodoo/odoo#33381
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>