Quick fix to issue with self buffs

casting_spell_targetid isn't guaranteed to be correct at that point in the code
Quick fix for now
Fixed issue with SE_StackingCommand_Overwrite

SE_StackingCommand_Overwite uses the calc to figure out the slot to check.
Seems that calc 202 is slot 1 and 201 is actually something special. It
could be any slot, but need further investigation, for now, just ignore it.