Modify Xtesting code according to NFV-TST version

This patch modifies Xtesting code to use the branch 2.6.1-fix-plu of NFV-TST.
This change is due to the issue [1] in ETSI NFV-TST.

[1] https://forge.etsi.org/rep/nfv/api-tests/-/issues/197

Issue-ID: SMO-119
Change-Id: I8e974c21c4221998dbd8bec829e351a3208c9db6
Signed-off-by: Koichi Edagawa <edagawa.kc@nec.com>
4 files changed