Fix the parser to take into account both the xs and xsd namespace prefixes

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

Author: c00kiemon5ter

src/saml2/saml.py

@@ -145,6 +145,12 @@ def set_type(self, typ):
             except AttributeError:
                 self._extatt['xmlns:xs'] = XS_NAMESPACE
 
+        if typ.startswith('xsd:'):
+            try:
+                self.extension_attributes['xmlns:xsd'] = XS_NAMESPACE
+            except AttributeError:
+                self._extatt['xmlns:xsd'] = XS_NAMESPACE
+
     def get_type(self):
         try:
             return self.extension_attributes[XSI_TYPE]