Scripts/World: removed deprecated emerald dragon scripts

sql/updates/world/custom/custom_2019_12_08_01_world.sql

@@ -0,0 +1,11 @@
+UPDATE `creature_template` SET `ScriptName`= '' WHERE `ScriptName` IN
+('npc_dream_fog',
+'npc_spirit_shade',
+'boss_ysondre',
+'boss_taerar',
+'boss_emeriss',
+'boss_lethon');
+
+DELETE FROM `spell_script_names` WHERE `ScriptName` IN 
+('spell_dream_fog_sleep',
+'spell_mark_of_nature');