DB: updated trainer tables for recent changes

sql/updates/world/4.3.4/2020_08_22_01_world.sql

@@ -0,0 +1,8 @@
+ALTER TABLE `creature_default_trainer` DROP PRIMARY KEY;
+RENAME TABLE `creature_default_trainer` TO `creature_trainer`;
+ALTER TABLE `creature_trainer`
+  ADD `MenuId` int(10) UNSIGNED NOT NULL DEFAULT '0' AFTER `TrainerId`,
+  ADD `OptionIndex` int(10) UNSIGNED NOT NULL DEFAULT '0' AFTER `MenuId`,
+  ADD PRIMARY KEY(`CreatureId`,`MenuId`,`OptionIndex`);
+
+DROP TABLE `gossip_menu_option_trainer`;