[MERGE] product_custom_attributes: 2 attr groups can include the same…

… field. In such case, present the field in the first group where it's found only instead of twice which leads to bugs

product_custom_attributes/product.py

@@ -110,8 +110,9 @@ def _build_attributes_notebook(self, cr, uid, attribute_group_ids, context=None)
         for group in grp_obj.browse(cr, uid, attribute_group_ids, context=context):
             page = etree.SubElement(notebook, 'page', string=group.name.capitalize())
             for attribute in group.attribute_ids:
-                toupdate_fields.append(attribute.name)
-                self._build_attribute_field(cr, uid, page, attribute, context=context)
+                if attribute.name not in toupdate_fields:
+                    toupdate_fields.append(attribute.name)
+                    self._build_attribute_field(cr, uid, page, attribute, context=context)
         return notebook, toupdate_fields
 
     def fields_view_get(self, cr, uid, view_id=None, view_type='form', context=None, toolbar=False, submenu=False):