tests/060: wait for master to start up

This is necessary to start sheepdog with all the nodes stably.

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
tests/048: fix vdi check output

Currently, 'collie vdi check' can repair objects in parallel, so we
cannot guarantee that sheep restores the first replica in this case.
This makes the test show the unique output in spite of the checked
order.

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>