Before this commit, in case you were in --dev-mode, if a json request crash,
it was wrongly intercepted and return a Internal Server Error with status 500
and without the JSON Response

For the change of http code, since it is only in dev mode, it could not impact
a production server (in theory) with custom code based on it.

After this commit, if your rpc fails, you will not have anymore a breakpoint in
the code to help the developer to debug. But you will have a status 200 on the
rpc request.

closes odoo/odoo#54668

X-original-commit: 534cca31
Signed-off-by: Olivier Dony (odo) <odo@openerp.com>
Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>