qapi/error.py: enable mypy checks

Signed-off-by: John Snow <jsnow@redhat.com>

Message-Id: <20210421192233.3542904-9-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
1 file changed