stack/erp5: Get rid of runUnitTest "Ignoring non existing bt5 path XXX/*" warnings.

stack/erp5/buildout.cfg

@@ -407,10 +407,8 @@ initialization =
   parts_directory = '''${buildout:parts-directory}'''
   repository_id_list = \
     '''${erp5_repository_list:repository_id_list}'''.split()[::-1]
-  os.environ['erp5_tests_bt5_path'] = ','.join(sum((
-    [bt5_path, os.path.join(bt5_path, '*')]
-    for bt5_path in (os.path.join(parts_directory, x, 'bt5')
-                     for x in repository_id_list)), []))
+  os.environ['erp5_tests_bt5_path'] = ','.join(
+    os.path.join(parts_directory, x, 'bt5') for x in repository_id_list)
   extra_path_list = '''${:extra-paths}'''.split()
   sys.path[:0] = sum((
     glob.glob(os.path.join(x, 'tests'))