RepoHook: do not list options twice during hash based approval

Instead of

  Do you want to allow this script to run (yes/yes-never-ask-again/NO)? (yes/always/NO)?

ask

  Do you want to allow this script to run (yes/always/NO)?

Change-Id: I5f5a2d0e88086a8d85e54fb8623a62d74a20956a
Signed-off-by: Jonathan Nieder <jrn@google.com>