[FIX] account_asset_disposal: env instead of cr in migration script

account_asset_disposal/migrations/10.0.1.0.0/pre-migration.py

@@ -1,6 +1,4 @@
 # -*- coding: utf-8 -*-
-# Copyright Stephane LE CORNEC
-# Copyright 2017 Tecnativa - Pedro M. Baeza <pedro.baeza@tecnativa.com>
 # Copyright 2017 Tecnativa - Luis M. Ontalba <luis.martinez@tecnativa.com>
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 
@@ -18,5 +16,5 @@ def cleanup_modules(cr):
 
 
 @openupgrade.migrate()
-def migrate(cr, version):
-    cleanup_modules(cr)
+def migrate(env, version):
+    cleanup_modules(env.cr)