[FIX] joint_buying_product: fix bug introduced by #106. do not raise …

…an error if user is not member of LOG group

joint_buying_product/models/res_partner.py

@@ -97,8 +97,10 @@ def _compute_joint_buying_grouped_order_qty(self):
 
     @api.constrains("joint_buying_use_category", "joint_buying_frequency_ids")
     def _check_joint_buying_use_category(self):
-        for partner in self.filtered(lambda x: not x.joint_buying_use_category):
-            if partner.mapped("joint_buying_frequency_ids.category_ids"):
+        for partner in self.filtered(lambda x: x.is_joint_buying):
+            if not partner.joint_buying_use_category and partner.mapped(
+                "joint_buying_frequency_ids.category_ids"
+            ):
                 raise ValidationError(
                     _(
                         "You can not uncheck 'Use Order Categories'"