message: Update functional RBF test to check replaceable flag
diff: @@ -427,6 +427,9 @@ class ReplaceByFeeTest(BitcoinTestFramework):
  tx1a_hex = txToHex(tx1a)
  tx1a_txid = self.nodes[0].sendrawtransaction(tx1a_hex, True)
  + # This transaction isn't shown as replaceable
  + assert_equal(self.nodes[0].getmempoolentry(tx1a_txid)['bip125-replaceable'], False)
  +
  # Shouldn't be able to double-spend
  tx1b = CTransaction()
  tx1b.vin = [CTxIn(tx0_outpoint, nSequence=0)]
  @@ -467,7 +470,10 @@ class ReplaceByFeeTest(BitcoinTestFramework):
  tx3a.vout = [CTxOut(int(0.9*COIN), CScript([b'c'])), CTxOut(int(0.9*COIN), CScript([b'd']))]
  tx3a_hex = txToHex(tx3a)
  - self.nodes[0].sendrawtransaction(tx3a_hex, True)
  + tx3a_txid = self.nodes[0].sendrawtransaction(tx3a_hex, True)
  +
  + # This transaction is shown as replaceable
  + assert_equal(self.nodes[0].getmempoolentry(tx3a_txid)['bip125-replaceable'], True)
  tx3b = CTransaction()
  tx3b.vin = [CTxIn(COutPoint(tx1a_txid, 0), nSequence=0)]
  