亡者奴仆调整

This tweak does three things.
First, it allows the Dead Thrall spell to be cast with one hand instead of two.
Second, it reduces the casting time to zero.
Third, it lowers the casting cost to one point.
It essentially overpowers the Dead Thrall spell.
This is my first tweak, so it's very simple.
Note: I will try to tweak other spells and weapons upon request. Although I'm a beginner, I can still make small changes. If there is demand, please leave a comment in the reply section specifying which spell you want tweaked and what changes you'd like.