Core/Spells: dropped Fingers of Frost charge drop spell script and use the new proc attribute instead.

sql/updates/world/4.3.4/2021_02_19_00_world.sql

@@ -0,0 +1,2 @@
+DELETE FROM `spell_script_names` WHERE `ScriptName`= 'spell_mage_fingers_of_frost_charges';
+UPDATE `spell_proc` SET `AttributesMask`= `AttributesMask`|0x10 WHERE `SpellId`= 44544;