python3-xmlschema: upgrade 2.3.0 -> 2.3.1

Changelog:
==========
 Meta-schema elements and groups ignore xsi:type attributes (issue #350)
 Use the meta-schemas only for validating XSD sources otherwise create dummy schemas

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>