This replxx object is pretty heavy and in debug build may slow down [1]
(although I cannot confirm 0.5s delay for each query in debug build) the
client and besides it is not required since ClickHouse-Extras/replxx#10,
which changes the behaviour of history_save(), and now it will not
update current session anymore, only save the history to the disk.
[1]: https://github.com/ClickHouse/ClickHouse/pull/13086#issuecomment-667719026