fix(DB/loot): Highland Fleshstalker drops (#6180)

Highland fleshstalkers have a bunch of 55+ blues on their loot table that they shouldn't be dropping.

- Closes azerothcore#6168
- Closes chromiecraft/chromiecraft#752

data/sql/updates/pending_db_world/rev_1622589180419433300.sql

@@ -0,0 +1,5 @@
+INSERT INTO `version_db_world` (`sql_rev`) VALUES ('1622589180419433300');
+
+SET @HIGHLAND_FLESHSTALKER = 2561;
+SET @REFERENCE_TABLE = 24017;
+DELETE FROM `creature_loot_template` WHERE `ENTRY` = @HIGHLAND_FLESHSTALKER AND `ITEM` = @REFERENCE_TABLE;