databases/mariadb106-server: Fix broken build WSREP=off

databases/mariadb106-server/pkg-plist

@@ -148,7 +148,7 @@ include/mysql/server/mysql/service_thd_rnd.h
 include/mysql/server/mysql/service_thd_specifics.h
 include/mysql/server/mysql/service_thd_timezone.h
 include/mysql/server/mysql/service_thd_wait.h
-include/mysql/server/mysql/service_wsrep.h
+%%WSREP%%include/mysql/server/mysql/service_wsrep.h
 include/mysql/server/mysql/services.h
 include/mysql/server/mysql_com.h
 include/mysql/server/mysql_com_server.h