bug#5345: Password asked when visiting a file in a lightweight checkout

[Juanma Barranquero]

With an up-to-date trunk build.

  emacs -Q
  C-x C-f C:/emacs/repo/test-lightweight/etc/NEWS <RET>
  => "Password for Juanma@C:"     -- Juanma being my user-name
  C-g
  C-x C-f C:/emacs/repo/test-lightweight/etc/NEWS <RET>
  => the file is visited OK.

It's happening for all files in lightweight checkouts:

  C:\emacs\repo\test-lightweight> bzr info
  Lightweight checkout (format: 2a or development-subtree)
  Location:
         light checkout root: .
    repository checkout root: C:/emacs/repo/trunk
          checkout of branch: sftp://bzr.savannah.gnu.org/srv/bzr/emacs/trunk/
           shared repository: C:/emacs/repo

  Related branches:
    public branch: sftp://bzr.savannah.gnu.org/srv/bzr/emacs/trunk
    parent branch: sftp://bzr.savannah.gnu.org/srv/bzr/emacs/trunk/

It does not happen for heavyweight checkouts, bound branches, or
normal (non-bound, non-checkout) branches.

    Juanma