test: add missing `expires` argument in DummyLocalizer.changeLanguage

This was not following the signature of the real method

product/ERP5Type/tests/utils.py

@@ -169,7 +169,7 @@ class DummyLocalizer:
 
   get_languages = get_supported_languages
 
-  def changeLanguage(self, lang):
+  def changeLanguage(self, lang, expires=None):
     self.lang = lang
 
   def translate(self, domain, msgid, lang=None, mapping=None, *args, **kw):