Currently, if account_peppol module is installed on a non-verified database,
it is not possible to register on `l10n_it_edi`, even on the test server.
That happens because we do not limit the demo mode to peppol.
This commit adds an additional check for the proxy_type when handling demo.
We wrap `make_request` in the decorator because it's used in many places in account_peppol,
so the condition has to be added inside the decorator.
closesodoo/odoo#149016
Signed-off-by: Laurent Smet (las) <las@odoo.com>