message: block: rm i temporary var
diff: @@ -131,11 +131,9 @@ Block.prototype.toHex = function (headersOnly) {
  Block.calculateTarget = function (bits) {
  var exponent = ((bits & 0xff000000) >> 24) - 3
  var mantissa = bits & 0x007fffff
  - var i = 28 - exponent
  -
  var target = new Buffer(32)
  target.fill(0)
  - target.writeUInt32BE(mantissa, i)
  + target.writeUInt32BE(mantissa, 28 - exponent)
  return target
  }
  