minor optimization to traceback

pkg/utils.go

@@ -62,10 +62,6 @@ func Reverse(s string) string {
 	return string(buf)
 }
 
-func Splice(s string, c rune, idx int) string {
-	return s[:idx] + string(c) + s[idx:]
-}
-
 func NextLoHi(M WavefrontComponent, I WavefrontComponent, D WavefrontComponent, score int, penalties Penalty) (int, int) {
 	x := penalties.X
 	o := penalties.O