This test failed to work properly because the fixes it came
with were not merged from upstream.
The test would fail with a spurious ER_LOCK_DEADLOCK error
for a conflict that happened earlier in the test execution,
while wsrep is disabled.
The original fix was to set THD::wsrep_conflict_state only
if wsrep is enabled (see wsrep_thd_set_conflict_state() in
sql/wsrep_mysqld.cc)