Remove unnecessary assignment in String#upto
@@ -422,7 +422,6 @@ class String
# both edges are all digits
bi = self.to_i(10)
ei = max.to_i(10)
- len = self.length
if (bi > 0 or bi == "0"*len) and (ei > 0 or ei == "0"*maxlen)
while bi <= ei
break if exclusive and bi == ei
