gossip: Do not use c_str() in the logger
gossip: Do not use c_str() in the logger

Use logger.info("{}", msg) instead.

Message-Id: <bb6fa10c2bee9ea5b3db60fa09cb81d8da957943@scylladb.com>

scylladb/scylla,duarten/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,duarten/scylla,avikivity/scylla,avikivity/scylla,duarten/scylla