save/restore auto_inc settings in galera_sst_mysqldump test

and remove redundant have_innodb.inc, it's included in
galera_cluster.inc anyway.

mysql-test/suite/galera/t/galera_sst_mysqldump.test

 --source include/galera_cluster.inc
---source include/have_innodb.inc
 
 --source suite/galera/include/galera_sst_set_mysqldump.inc
 
+--let $node_1=node_1
+--let $node_2=node_2
+--source include/auto_increment_offset_save.inc
+
 --source suite/galera/include/galera_st_disconnect_slave.inc
 
 # We set the required mysqldump SST options here so that they are used every time the server is restarted during the test
@@ -14,4 +17,5 @@
 --source suite/galera/include/galera_st_kill_slave.inc
 --source suite/galera/include/galera_st_kill_slave_ddl.inc
 
+--source include/auto_increment_offset_restore.inc
 --source suite/galera/include/galera_sst_restore.inc