- usage of the include/force_myisam_default.inc in only some tests
   of ndb_memcache/ suite causes mysqld restarts without restarting
   the rest of the cluster. This introduces a race condition between
   when the restarted mysqld synchronizes dictionary with the cluster
   and when mtrpl checks if the ndb_memcache database exists or not.
   Thus causing the ndb_memcache_metadata.sql file to be loaded
   although the ndb_memcache database already exist.
 - Fix by removing the usage of include/force_myisam_default.inc from
   the ndb_memcache suite as none of it depends on myisam. This
   avoids the restarts and thus hides the race condition.
 - Leaving as an exercise for the future the good idea to
   fix mtr.pl to restart the whole configuration for ndb_memcache tests
   if they need to run with different mysqld options.