Add fast_forward_grace_close test to groups.json

test/tap/groups/groups.json

@@ -135,6 +135,7 @@
   "test_cluster_sync_mysql_servers-t" : [ "default-g3","mysql-auto_increment_delay_multiplex=0-g3","mysql-multiplexing=false-g3","mysql-query_digests=0-g3","mysql-query_digests_keep_comment=1-g3" ],
   "test_cluster_sync-t" : [ "default-g3","mysql-auto_increment_delay_multiplex=0-g3","mysql-multiplexing=false-g3","mysql-query_digests=0-g3","mysql-query_digests_keep_comment=1-g3" ],
   "test_com_binlog_dump_enables_fast_forward-t" : [ "default-g3","mysql-auto_increment_delay_multiplex=0-g3","mysql-multiplexing=false-g3","mysql-query_digests=0-g3","mysql-query_digests_keep_comment=1-g3" ],
+  "fast_forward_grace_close_libmysql-t" : [ "default-g3","mysql-auto_increment_delay_multiplex=0-g3","mysql-multiplexing=false-g3","mysql-query_digests=0-g3","mysql-query_digests_keep_comment=1-g3" ],
   "test_com_register_slave_enables_fast_forward-t" : [ "default-g3","mysql-auto_increment_delay_multiplex=0-g3","mysql-multiplexing=false-g3","mysql-query_digests=0-g3","mysql-query_digests_keep_comment=1-g3" ],
   "test_com_reset_connection_com_change_user-t" : [ "default-g3","mysql-auto_increment_delay_multiplex=0-g3","mysql-multiplexing=false-g3","mysql-query_digests=0-g3","mysql-query_digests_keep_comment=1-g3" ],
   "test_connection_annotation-t" : [ "default-g3","mysql-auto_increment_delay_multiplex=0-g3","mysql-multiplexing=false-g3","mysql-query_digests=0-g3","mysql-query_digests_keep_comment=1-g3" ],