[xsd gen] Stop setting broken type on scheme identifier attribute

Better nothing than a broken type (we could also add 'xsd:' but this is flaky).

entities/profile_generation.py

@@ -250,7 +250,6 @@ class SEDA2XSDExport(EntityAdapter):
             scheme_attr = self.element(
                 'xsd:attribute',
                 attributes={'name': xsattr.local_name,
-                            'type': xsattr.textual_content_type,
                             'fixed': target_value.scheme.absolute_url()})
             type_element.append(scheme_attr)