fix a tiny memory leak
fix a tiny memory leak

The edge swapper object was
not being freed.

yangf4/core,YetAnotherMinion/core,yangf4/core,YetAnotherMinion/core,YetAnotherMinion/core,YetAnotherMinion/core,yangf4/core,yangf4/core,yangf4/core,YetAnotherMinion/core