Update test/test_definednamespace.py
Update test/test_definednamespace.py

Co-authored-by: Iwan Aucamp <9e0997e514d2c9142ff540255e89ad86035620fe@gmail.com>
RDFLib/rdflib,RDFLib/rdflib,RDFLib/rdflib,RDFLib/rdflib