Fix another too greedy regex in SAMLFrontend.register_endpoints.

Author: Rebecka Gulliksson

src/satosa/frontends/saml2.py

@@ -345,7 +345,7 @@ def _register_endpoints(self, providers):
                     valid_providers = "{}|^{}".format(valid_providers, provider)
                 valid_providers = valid_providers.lstrip("|")
                 parsed_endp = urlparse(endp)
-                url_map.append(("%s/%s$" % (valid_providers, parsed_endp.path),
+                url_map.append(("(%s)/%s$" % (valid_providers, parsed_endp.path),
                                 functools.partial(self.handle_authn_request, binding_in=binding)))
 
         return url_map