Merge pull request FISCO-BCOS#2438 from ywy2090/master-2.0

fix illegal instruction error

fix viewchange failed (FISCO-BCOS#2332)

use wget to modify curl (FISCO-BCOS#2198)

Update README_EN.md

update boost versiont to 1.6.8 (FISCO-BCOS#1983)

update build_chain tips (FISCO-BCOS#1888)

Merge pull request FISCO-BCOS#1830 from FISCO-BCOS/release-2.7.1

sync code from release-2.7.1 into master

FISCO-BCOS v2.7.0

fix not trigger viewchange bug even when collect enough consistent vi…

…ewchange req (FISCO-BCOS#1798)

* fix not trigger viewchange bug even when collect enough consistent viewchange req

* increase the idle time interval

* fix coredump when accessing topics() function of ChannelSession concurrently

add getBlockTransactionReceipts