Improve response data of test_routers_client

The response data of test_routers_client are edited in order to be
consistent with the Reference API document [1]

[1] https://docs.openstack.org/api-ref/network/v2/index.html

Closes-Bug: 1838005
Change-Id: I9f5e57a3114ac047f87762def08b165bf377b600
1 file changed