better erase message buffer
better erase message buffer

zuoshifan/emacs.d,zuoshifan/emacs.d,zuoshifan/emacs.d,zuoshifan/emacs.d,zuoshifan/emacs.d,zuoshifan/emacs.d,zuoshifan/emacs.d,zuoshifan/emacs.d,zuoshifan/emacs.d