Use tryton.cfg to register in the Pool

modules/account_tax_non_deductible/__init__.py

@@ -1,16 +1,2 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
-
-from trytond.pool import Pool
-
-from . import account
-
-__all__ = ['register']
-
-
-def register():
-    Pool.register(
-        account.TaxTemplate,
-        account.Tax,
-        account.InvoiceLine,
-        module='account_tax_non_deductible', type_='model')

modules/account_tax_non_deductible/tryton.cfg

@@ -6,3 +6,9 @@ depends:
     ir
 xml:
     account.xml
+
+[register]
+model:
+    account.TaxTemplate
+    account.Tax
+    account.InvoiceLine