Update setup.rst (#307)

The document has something wrong in PySAML2 specific files and configuration:
https://djangosaml2.readthedocs.io/contents/setup.html#pysaml2-specific-files-and-configuration

The example put `allow_unknown_attributes` in `service.sp`, however, in pysaml2, `allow_unknown_attributes` is at root level, since `allow_unknown_attributes` was put at `COMMON_ARGS`:
https://github.com/IdentityPython/pysaml2/blob/master/src/saml2/config.py

Author: oakmegaeddie

docs/source/contents/setup.rst

@@ -465,6 +465,10 @@ settings.py file under the SAML_CONFIG option. We will see a typical configurati
     # directory with attribute mapping
     'attribute_map_dir': path.join(BASEDIR, 'attribute-maps'),
 
+    # Permits to have attributes not configured in attribute-mappings
+    # otherwise...without OID will be rejected
+    'allow_unknown_attributes': True,
+
     # this block states what services we provide
     'service': {
         # we are just a lonely SP
@@ -526,10 +530,6 @@ settings.py file under the SAML_CONFIG option. We will see a typical configurati
             # a respective SAML Authentication Request.
             'allow_unsolicited': False,
 
-            # Permits to have attributes not configured in attribute-mappings
-            # otherwise...without OID will be rejected
-            'allow_unknown_attributes': True,
-
             # in this section the list of IdPs we talk to are defined
             # This is not mandatory! All the IdP available in the metadata will be considered instead.
             'idp': {