We actually want to advise git-commit
Don't show commit options unless forced

Passing a prefix command to "c" in the Magit buffer will cause the
options to be shown. I don't miss the 'amend' functionality for two
reasons:

1) I can call it explicitly from the commit options; and
2) I can use `C-c C-a` from within the commit buffer to make that commit
an amend anyway.

Works around magit/magit#766