Core/Spell: Fix Blade Warding Damage Proc (Weapon Enchant)

fixes the damage proc of the weapon enchant Blade Ward.

the damage depends on active aura stacks after you have parried. 

for more informations click http://www.wowwiki.com/Enchant_Weapon_-_Blade_Ward

TODO: spell has to crit with crit chance of the caster - tried to fix this but it doesn't seem to work