require SQL_BIG_SELECTS=1

There was a previous test that leaves a non-default (small) max_join_size.
Fixed by re-setting the max_join_size to default when the test is over.


mysql-test/extra/rpl_tests/rpl_row_charset.test:
  Bug #31524: side effects of previous testsuites fixed
mysql-test/suite/rpl/r/rpl_row_charset.result:
  Bug #31524: side effects of previous testsuites fixed
mysql-test/suite/rpl/r/rpl_row_charset_innodb.result:
  Bug #31524: side effects of previous testsuites fixed
mysql-test/suite/rpl_ndb/r/rpl_ndb_charset.result:
  Bug #31524: side effects of previous testsuites fixed