erp5_km_ui_test_data: fix coding style test

one coding test failed with

FAIL: test_rebuild_business_template (CodingStyleTest.CodingStyleTest erp5_km_ui_test_data.test_rebuild_business_template)
Try to rebuild business template to catch packaging errors and make sur output is stable.
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Traceback (most recent call last):
  File "/srv/slapgrid/slappart38/t/ekc/soft/bf5e42cc41d1a5fa8ce16a35cbd8a699/parts/erp5/product/ERP5Type/tests/CodingStyleTestCase.py", line 226, in test_rebuild_business_template
    self.assertEqual(diff_files, [])
AssertionError: Lists differ: ['modified: erp5_km_ui_test_data/PathTempl[62 chars]xml'] != []

First list contains 1 additional elements.
First extra element 0:
'modified: erp5_km_ui_test_data/PathTemplateItem/web_site_module/predecessor_test_web_site/discussions.xml'

+ []
- ['modified: '
-  'erp5_km_ui_test_data/PathTemplateItem/web_site_module/predecessor_test_web_site/discussions.xml']