sql/ha_ndbcluster.cc:
  Additional fixes for WL#1892, disable autodiscover during add/drop index
sql/ha_ndbcluster.h:
  Additional fixes for WL#1892, disable autodiscover during add/drop index
sql/sql_table.cc:
  Additional fixes for WL#1892, removed double commit + added call to create_handler_files after create/drop index
mysql-test/r/ndb_alter_table_row.result:
  Additional fixes for WL#1892, changed test case
mysql-test/t/ndb_alter_table_row.test:
  Additional fixes for WL#1892, changed test case