当为比特币 rpc 调用 getblocktemplate 时，返回的 json（字典）响应似乎不再包含“coinbasetxn”键。coinbase 交易现在在哪里？
示例响应getblocktemplate()：
{'height': 453825, 'mintime': 1487548277, 'version': 536870912, 'coinbasevalue': 1306788433, 'previousblockhash': '0000000000000000019ca63484f8251b15647869d4c36ec5b201277f3e2aa70b', 'rules': ['csv'], 'sigoplimit': 20000, ' weightlimit': 4000000, 'mutable': ['time', 'transactions', 'prevblock'], 'target': '0000000000000000027e93000000000000000000000000000000000000000000', 'bits': '18027e93', 'longpollid': '0000000000000000019ca63484f8251b15647869d4c36ec5b201277f3e2aa70b20632', 'vbrequired' ：0，'noncerange'：'00000000ffffffff'，'curtime'：1487550914，'coinbaseaux'：{'flags'：''}，'transactions'：[{'depends': [], 'data': '0100000001fb5b6947704577fd09260adf7f80c92ada4776ca7674a5fb8af40df3c747293a010000006a473044022048aab0d8bd6c127696ce2cceb42693af2ae8eec561a33acf43577193070cd965022043667ae3c25661d251133b75fbefa8b9b5d3dddeedae028c90899c642f693479012103c7b4ed6b91df7eb7d2bd62a6257dd2e2fa79d07e81080b7e95bcd3d9e448f464feffffff02504b4500000000001976a914fd09ed8b3099ee1f67693c3c6c25ca7ecb150fcf88ac48c5374e000000001976a914a97d5d95cd416dc0f734cb028f0785a4f545cea988ac96ec0600', 'txid': '2ed056bed0417623433d6b600dfb6afcebb8c22b1f42b6e776cf8263289fb5ac', 'sigops': 2, 'weight': 900, 'fee': 204345, 'hash': '2ed056bed0417623433d6b600dfb6afcebb8c22b1f42b6e776cf8263289fb5ac'}, { '取决于'：[]，'数据'：'01000000011e7d9c88fe30a4c9fa1ec229e7c11704ec0185e36……（……其余交易……）