erp5_payroll_l10n_fr: fix Cannot decode using encoding "ascii" warning

bt5/erp5_payroll_l10n_fr/TestTemplateItem/portal_components/test.erp5.testSimplifiedPayslipReport.py

+# -*- coding: utf-8 -*-
 #############################################################################
 #
 # Copyright (c) 2002-2015 Nexedi SA and Contributors. All Rights Reserved.

bt5/erp5_payroll_l10n_fr/TestTemplateItem/portal_components/test.erp5.testSimplifiedPayslipReport.xml

@@ -45,10 +45,7 @@
         <item>
             <key> <string>text_content_warning_message</string> </key>
             <value>
-              <tuple>
-                <string>W:107,  0: Cannot decode using encoding "ascii", unexpected byte at position 17 (invalid-encoded-data)</string>
-                <string>W:152,  0: Cannot decode using encoding "ascii", unexpected byte at position 47 (invalid-encoded-data)</string>
-              </tuple>
+              <tuple/>
             </value>
         </item>
         <item>