fix(ycsb): remove usage of cql_ip_address from YcsbStatsPublisher
fix(ycsb): remove usage of cql_ip_address from YcsbStatsPublisher

cause of this usage on each line of stats being used, we copy
back and forth the scylla.yaml of the loader, for no good reason
blowing up the logs, and taking lots of cpu from the test runner
(which is shared in perf test anyhow)

scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests