[FIX] account: Perform B2B/B2C overlapping check per user

Steps to reproduce the problem:

- Have user A with B2B group.
- Have user B with B2C group.
- Add simultaneously on both - via write - another group (or call `_check_one_user_type`).

Expected result:

- No problem

Got result:

- Error "A user cannot have both Tax B2B and Tax B2C..."

That's because the check is performed for more than one user each time, while it has
to be record per record. The implementation of `_has_multiple_groups` actually
checks if the passed recordset is only one record, and if not, it looks directly for all
existing users, so also the case of both users A and B being in the same B2x group, but
having a 3rd user in the other group will fail.

Revisiting the query in `_has_multiple_groups`, there's a hidden error when you use it
for only one ID because a missing space.

closes odoo/odoo#44300

X-original-commit: 83f104b2f2fc1345ad067430466c004697a91db9
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

0 files changed, 0 insertions, 0 deletions