MDEV-22443 wsrep::runtime_error on START TRANSACTION

This happens with global wsrep_on disabled and local wsrep_on enabled.
The fix consists in avoiding sync wait when global wsrep_on is
disabled.

mysql-test/suite/wsrep/r/MDEV-22443.result

+SET SESSION wsrep_sync_wait=15;
+SET SESSION wsrep_on=1;
+START TRANSACTION READ WRITE;

mysql-test/suite/wsrep/t/MDEV-22443.cnf

+!include ../my.cnf
+
+[mysqld.1]
+wsrep-on=OFF
+binlog-format=ROW
+wsrep-provider=none
+wsrep-cluster-address='gcomm://'
+innodb_autoinc_lock_mode=2

mysql-test/suite/wsrep/t/MDEV-22443.test

+#
+# MDEV-22443: terminate called after throwing an instance of
+# 'wsrep::runtime_error' in std::terminate on START TRANSACTION
+#
+
+--source include/have_innodb.inc
+--source include/have_wsrep.inc
+--source include/have_binlog_format_row.inc
+
+SET SESSION wsrep_sync_wait=15;
+SET SESSION wsrep_on=1;
+START TRANSACTION READ WRITE;

sql/wsrep_mysqld.cc

@@ -1092,7 +1092,7 @@ bool wsrep_must_sync_wait (THD* thd, uint mask)
   mysql_mutex_lock(&thd->LOCK_thd_data);
   ret= (thd->variables.wsrep_sync_wait & mask) &&
     thd->wsrep_client_thread &&
-    thd->variables.wsrep_on &&
+    WSREP_ON && thd->variables.wsrep_on &&
     !(thd->variables.wsrep_dirty_reads &&
       !is_update_query(thd->lex->sql_command)) &&
     !thd->in_active_multi_stmt_transaction() &&