saml frontend: remove metadata param when applying the set policy

This param was deprecated by pysaml2 v6.3.0

Signed-off-by: Ivan Kanakarakis <ivan.kanak@gmail.com>

src/satosa/frontends/saml2.py

@@ -282,7 +282,7 @@ def _get_approved_attributes(self, idp, idp_policy, sp_entity_id, state):
         for aconv in attrconvs:
             if aconv.name_format == name_format:
                 all_attributes = {v: None for v in aconv._fro.values()}
-                attribute_filter = list(idp_policy.restrict(all_attributes, sp_entity_id, idp.metadata).keys())
+                attribute_filter = list(idp_policy.restrict(all_attributes, sp_entity_id).keys())
                 break
         attribute_filter = self.converter.to_internal_filter(self.attribute_profile, attribute_filter)
         msg = "Filter: {}".format(attribute_filter)