This trace back raises when we try to create delivery price rule,
while delivery product is not selected in the delivery carrier.
Steps to produce:
* Install delivery,sales modules
* Open Sales/Configuration/Shipping Methods
* Create a new shipping method keep provider as 'Based on Rules'
* Try to add a line for pricing
* At this moment trace back raises ('Expected singleton: res.currency')
We resolve this issue by not formatting the name if the currency does
not exist yet, as the currency is related to the one of the product.
Sentry :- 4067992652
closesodoo/odoo#119958
X-original-commit: d20431758c0c4943394a63250ad0a83894b795c8
Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>