config: disable new sharding algorithm
config: disable new sharding algorithm

It still has problems:
 - while resharding a very large leveled compaction strategy table, a huge
   amount of tiny sstables are generated, overwhelming the file descriptor
   limits
 - there is a large impact on read latency while resharding is going on

(cherry picked from commit cf27d4441268ced3e8b9371f50eb2711616b13fa)

(forward-ported from branch-1.6)

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