Do not limit the single_logout_service results

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

Author: c00kiemon5ter

src/saml2/mdstore.py

@@ -1233,8 +1233,6 @@ def single_logout_service(self, entity_id, binding=None, typ=None):
         # IDP + SP
         if typ is None:
             raise AttributeError("Missing type specification")
-        if binding is None:
-            binding = BINDING_HTTP_REDIRECT
         return self.service(entity_id, "%s_descriptor" % typ,
                             "single_logout_service", binding)