Fix the test for WebDAV.

See merge request !1926
4 jobs for zope4py3 in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Zope4Py3

00:56:38

failed ERP5.CodingStyleTest-Zope4Py3-py2

00:54:59

failed ERP5.UnitTest-Zope4Py3

02:27:59

failed ERP5.UnitTest-Zope4Py3-Py2

01:30:55