TxIn: don't set sequence to null if 0xffffffff

Transaction.js

@@ -433,7 +433,7 @@ Transaction.prototype.getStandardizedObject = function getStandardizedObject() {
         hash: buffertools.reverse(new Buffer(txin.getOutpointHash())).toString('hex'),
         n: txin.getOutpointIndex()
       },
-      sequence: (txin.q === 0xffffffff) ? null : txin.q
+      sequence: txin.q
     };
     if (txin.isCoinBase()) {
       txinObj.coinbase = txin.s.toString('hex');