Fix testcase 'test_create_subnet_with_two_host_routes' failed

Fix bug 1179348

Change-Id: I0cd5d303da0f394cec173aeee52efcd337282c94
Signed-off-by: Christoph Thiel <c.thiel@telekom.de>
Merge "Fix testcase 'test_create_subnet_with_two_host_routes' failed" into stable/grizzly