[16.0][FIX] sale_order_type: assign base company in non-multicompany environments

[iTecan]

We have modified the following company field in data/default_type.xml from:

    <field name="company_id" eval="False" />

To:

    <field name="company_id" ref="base.main_company" />

This change is due to the fact that in an environment without the multi-company parameter, the warehouse field cannot be filled because it is not assigned to a company.