Fix a bug in raftnode's log synchronization (#703)
Fix a bug in raftnode's log synchronization (#703)

(#676)
yvxiang/dfs,lylei/dfs,yvxiang/dfs,bluebore/dfs,bluebore/bfs,baidu/bfs,baidu/bfs,bluebore/bfs,linyvxiang/dfs,yvxiang/dfs,yvxiang/dfs,yvxiang/coverage_for_bfs,lylei/dfs,yvxiang/coverage_for_bfs,yvxiang/coverage_for_bfs,bluebore/bfs,bluebore/dfs,yvxiang/coverage_for_bfs,linyvxiang/dfs,lylei/dfs,bluebore/dfs,baidu/bfs,linyvxiang/dfs,lylei/dfs,baidu/bfs