`string-to-int-signedness-cast.yaml` false positives

[GrosQuildu]

The string-to-int-signedness-cast.yaml rule should exclude from results casts that have explicit checks on a value. eg

	a, err := strconv.ParseInt(X, 10, 64)
	if err != nil {
		panic(err)
	}
	if a < 0 {
		panic("X")
	}
	b := uint64(a)

This is marked as truncating cast, but the if makes it valid.