Enables compatibility with MySQL 5.6 system and status variable sources
(SHOW statements, INFORMATION_SCHEMA tables) for tests using the scenario of
ndb_rpl_multi_binlog_update configuration file.

MTR method check_testcase() uses statements which are only available in MySQL
5.6 such as "SELECT * FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES". Other tests use
default mysqld configuration by including default_mysqld.cnf where compatibility
with MSQL 5.6 is enabled. The test scenario specified in
ndb_rpl_multi_binlog_update configuration file uses non default configurations
for mysqld servers and therefore it cannot include default_mysqld.cnf. Enable
explicitly the compatibility with MySQL 5.6 in the ndb_rpl_multi_binlog_update
configuration file.

Reviewed-by : Magnus Blaudd <magnus.blaudd@oracle.com>