Update Xtesting to 0.41
Update Xtesting to 0.41

It includes an enhancement about logger (needed by sdnvpn).

Change-Id: I05173d2f5b86e12f6badc83e9ee71ecd5898ecee
Signed-off-by: Cédric Ollivier <d48310251a4a484d041bc5d09a9ac4d86d20f793@orange.com>

opnfv/functest,opnfv/functest