Fix MTR test wsrep.variables

Require galera_have_debug_sync.inc and re-record to include new
variables exposed by latest galera library.

mysql-test/suite/wsrep/r/variables.result

@@ -48,6 +48,8 @@ wsrep_flow_control_paused_ns	#
 wsrep_flow_control_paused	#
 wsrep_flow_control_sent	#
 wsrep_flow_control_recv	#
+wsrep_flow_control_active	#
+wsrep_flow_control_requested	#
 wsrep_cert_deps_distance	#
 wsrep_apply_oooe	#
 wsrep_apply_oool	#
@@ -63,6 +65,7 @@ wsrep_cert_interval	#
 wsrep_open_transactions	#
 wsrep_open_connections	#
 wsrep_incoming_addresses	#
+wsrep_debug_sync_waiters	#
 wsrep_applier_thread_count	#
 wsrep_cluster_capabilities	#
 wsrep_cluster_conf_id	#
@@ -109,6 +112,8 @@ wsrep_flow_control_paused_ns	#
 wsrep_flow_control_paused	#
 wsrep_flow_control_sent	#
 wsrep_flow_control_recv	#
+wsrep_flow_control_active	#
+wsrep_flow_control_requested	#
 wsrep_cert_deps_distance	#
 wsrep_apply_oooe	#
 wsrep_apply_oool	#
@@ -124,6 +129,7 @@ wsrep_cert_interval	#
 wsrep_open_transactions	#
 wsrep_open_connections	#
 wsrep_incoming_addresses	#
+wsrep_debug_sync_waiters	#
 wsrep_applier_thread_count	#
 wsrep_cluster_capabilities	#
 wsrep_cluster_conf_id	#

mysql-test/suite/wsrep/t/variables.test

 --source include/have_wsrep.inc
 --source include/force_restart.inc
 --source include/have_innodb.inc
+--source include/galera_have_debug_sync.inc
 
 SET @wsrep_provider_options_saved= @@global.wsrep_provider_options;
 SET @wsrep_cluster_address_saved= @@global.wsrep_cluster_address;