raft: replication test: custom next leader noop for same
raft: replication test: custom next leader noop for same

If custom specified leader is same do nothing.

Signed-off-by: Alejo Sanchez <004be06a28e38b437b038f9b5c0b9f5758b792e9@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla