将存证例子跑起来后报错，但后台能正常部署HelloWorld合约

[kixiong]

抛出如下异常：

2018-08-27 18:09:22.088 [pool-4-thread-1] DEBUG ChannelEthereumService(ChannelEthereumService.java:54) - Ethereum Response:94f87176ff8e475297de1892640f2e63 -1
java.util.concurrent.ExecutionException: com.fasterxml.jackson.databind.JsonMappingException: No content to map due to end-of-input
at [Source: ; line: 1, column: 0]
at java.util.concurrent.CompletableFuture.reportGet(Unknown Source)
at java.util.concurrent.CompletableFuture.get(Unknown Source)
at org.bcos.evidence.app.BcosApp.deployContract(BcosApp.java:88)
at org.bcos.evidence.app.Main.main(Main.java:39)
Caused by: com.fasterxml.jackson.databind.JsonMappingException: No content to map due to end-of-input
at [Source: ; line: 1, column: 0]
at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:270)
at com.fasterxml.jackson.databind.ObjectMapper._initForReading(ObjectMapper.java:3854)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3799)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2858)
at org.bcos.web3j.protocol.channel.ChannelEthereumService.send(ChannelEthereumService.java:56)
at org.bcos.web3j.protocol.core.Request.send(Request.java:93)
at org.bcos.web3j.tx.RawTransactionManager.signAndSend(RawTransactionManager.java:129)
at org.bcos.web3j.tx.RawTransactionManager.sendTransaction(RawTransactionManager.java:92)
at org.bcos.web3j.tx.TransactionManager.executeTransaction(TransactionManager.java:45)
at org.bcos.web3j.tx.ManagedTransaction.send(ManagedTransaction.java:42)
at org.bcos.web3j.tx.Contract.executeTransaction(Contract.java:302)
at org.bcos.web3j.tx.Contract.create(Contract.java:434)
at org.bcos.web3j.tx.Contract.deploy(Contract.java:409)
at org.bcos.web3j.tx.Contract.lambda$deployAsync$4(Contract.java:451)
at org.bcos.web3j.utils.Async.lambda$run$29(Async.java:22)
at java.util.concurrent.CompletableFuture$AsyncRun.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Exception in thread "main" java.lang.NullPointerException
at org.bcos.evidence.app.BcosApp.deployContract(BcosApp.java:92)
at org.bcos.evidence.app.Main.main(Main.java:39)
2018-08-27 18:09:23.656 [Thread-1] DEBUG ChannelConnections(ChannelConnections.java:378) - try connect to: 192.168.88.139:8302

查看后台中的一个节点报如下的错误：
ERROR|2018-08-27 08:57:07:995|handlePrepareMsg: idx=1,view=185,blk=1,hash=b8707725…,from=1Recv an illegal prepare, err leader