[FIX] microsoft_account: always return dictionary on API calls

The return type of _do_request is inconsistent when an error is
encountered. This causes issues when the callers expect the return
type to be a dictionary consistently.

We fix this by always returning an empty dictionary for the request
response when encountering an error

sentry-4339147124

closes odoo/odoo#129872

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>