tests/unit: Bump test-replication timeout to 60 seconds

tests/unit: Bump test-replication timeout to 60 seconds

We're seeing timeouts for this test on CI runs (specifically for
ubuntu-20.04-s390x-all). It doesn't fail consistently, but even the
successful runs take about 27 or 28 seconds, which is not very far from
the 30 seconds timeout.

Bump the timeout a bit to make failure less likely even on this CI host.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20240125165803.48373-1-kwolf@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 63b18312d14ac984acaf13c7c55d9baa2d61496e)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>