ipv6: fix @ipv6_add_static_address_manually_not_active test to wait
The test is supposed to check that NetworkManager does not add a link local address. It needs to wait longer to ensure that this doesn't happen. The previous form did this wrong, which can also be seen because the test still passes against current master of NetworkManager -- although it would be expected to fail. Fix it.
Fixes: e12de017
This is a follow up for #152, which got this wrong.
I tested it, it seems to work. I recommend to merge this patch right away (if you agree), but note that this test is supposed to fail with current master of NetworkManager. It already tests new behavior, that will be merge soon. That is fine.