repair: replace_with_repair: convert to coroutine
repair: replace_with_repair: convert to coroutine

Prepare to futurizing update_normal_tokens.

Signed-off-by: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@scylladb.com>

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