storage_service: Fix default ring_delay time
storage_service: Fix default ring_delay time

It is 30 seconds instead of 5 seconds by default. To align with c*.

Pleas note, after this a node will takes at least 30 seconds to complete
a bootstrap.

duarten/scylla,raphaelsc/scylla,kjniemi/scylla,avikivity/scylla,kjniemi/scylla,scylladb/scylla,scylladb/scylla,kjniemi/scylla,duarten/scylla,scylladb/scylla,raphaelsc/scylla,avikivity/scylla,avikivity/scylla,raphaelsc/scylla,scylladb/scylla,duarten/scylla