production_lot_custom_attributes: quick create attribute from group form, KeyError: 'attribute_type'

[Leonardo Pistone]

To reproduce:

Install production_lot_custom_attributes on v6.1.

In an Attribute Group, "Create" or "Create and edit" an attribute

  File "/home/lpistone/work/env/6.1/extra/base_custom_attributes/custom_attributes.py", line 254, in create
    if vals['attribute_type'] == 'select':
KeyError: 'attribute_type'

Thanks!