MDEV-30013 : Assertion `state() == s_aborting || state() == s_must_replay' failed in int wsrep::transaction::after_rollback()

This must be some kind of merge error because at ha_check_engine
we just find out used engine or default engine. There is
no need to roll-back transaction here even if engine is not
supported as it will be handled later.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>