[FIX] l10n_be_cooperator: Do not use user_id in mail template
[FIX] l10n_be_cooperator: Do not use user_id in mail template

user_id doesn't exist on objects. I'm not sure how this ever worked.

Signed-off-by: Carmen Bianca Bakker <f1196a8a993e28d05bd187b7b130720e5dd34147@coopiteasy.be>

OCA/l10n-belgium,OCA/l10n-belgium