[password autofill] Fix bug in LoginDatbase migration code.

Users were getting the new columns added, but were not having the
version numbers updated.

BUG=295851
R=shess@chromium.org

Review URL: https://codereview.chromium.org/24146008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224781 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224781