DB/Spell: Dreadsteed - Flame visual

By @Killyana

Closes #14413

sql/updates/world/2015_03_21_01_world.sql

@@ -0,0 +1,5 @@
+DELETE FROM `spell_linked_spell` WHERE `spell_trigger` = 23161;
+INSERT INTO `spell_linked_spell` VALUES (23161, 31725, 0, 'Summon Nightmare');
+
+DELETE FROM `spell_linked_spell` WHERE `spell_trigger` = 5784;
+INSERT INTO `spell_linked_spell` VALUES (5784, 31725, 0, 'Summon felsteed');