El Capitan Mac: /usr/bin/login tries to run /bin/false
I had the same problem, with emacs giving me "Error (use-package): exec-path-from-shell :init: Searching for program: no such file or directory, /bin/false" on startup.
However, I noticed that this only happens when running Emacs (installed from emacsformacosx) from the Dock or Spotlight. If I ran it from my Terminal, or by clicking on it in Applications in finder, it worked fine. 

After a restart, the problem was resolved. I suspect that Dock and Spotlight held on to my original default shell, and after a restart, they used the new value (changed from /bin/false to /bin/zsh).