Clear checklist if empty
Clear checklist if empty

myawan/bfs-1,lylei/dfs,myawan/bfs-1,lylei/dfs,baidu/bfs,lylei/dfs,yvxiang/coverage_for_bfs,baidu/bfs,bluebore/dfs,bluebore/dfs,linyvxiang/dfs,00k/ToyDFS,yvxiang/coverage_for_bfs,yvxiang/dfs,imotai/bfs,linyvxiang/dfs,yvxiang/dfs,myawan/bfs-1,yvxiang/dfs,bluebore/bfs,bluebore/bfs,bluebore/bfs,00k/ToyDFS,lylei/dfs,baidu/bfs,myawan/bfs-1,imotai/bfs,yvxiang/coverage_for_bfs,bluebore/dfs,baidu/bfs,yvxiang/coverage_for_bfs,yvxiang/dfs,linyvxiang/dfs,imotai/bfs