Bump mgmt submodule HEAD

Changes:

commit 29ae2430f0e2b538477b49b4b9f8432780ddf60e
Author: Tomasz Grabiec <tgrabiec@cloudius-systems.com>

    httpserver: add missing module.py

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>