Bad file paths in PySAML2 configuration cause tracebacks

[dataflake]

Example:

  File "/home/jens/src/samltest/src/Products.SAML2Plugins/src/Products/SAML2Plugins/configuration.py", line 309, in getPySAML2Configuration
    cfg.load(copy.deepcopy(self.getConfiguration()))
  File "/home/jens/src/samltest/eggs/pysaml2-7.4.2-py3.10.egg/saml2/config.py", line 337, in load
    self.load_complex(cnf)
  File "/home/jens/src/samltest/eggs/pysaml2-7.4.2-py3.10.egg/saml2/config.py", line 265, in load_complex
    acs = ac_factory(cnf.get("attribute_map_dir"))
  File "/home/jens/src/samltest/eggs/pysaml2-7.4.2-py3.10.egg/saml2/attribute_converter.py", line 65, in ac_factory
    for fil in sorted(os.listdir(path)):
FileNotFoundError: [Errno 2] No such file or directory: 'etc/attribute_maps'