Bypass NoneType errors when creating router in rally
Bypass NoneType errors when creating router in rally

It converts private subnet name to str as it's mandary till [1].
It could be reverted as soon as [2] is merged in snaps.

[1] https://gerrit.opnfv.org/gerrit/#/c/56091/
[2] https://gerrit.opnfv.org/gerrit/#/c/56171/

Change-Id: Ia728415207f8ecb5b5ac55982f82337c45671c4c
Signed-off-by: Cédric Ollivier <d48310251a4a484d041bc5d09a9ac4d86d20f793@orange.com>

opnfv/functest,opnfv/functest