Icc105c39e introduced severe security problem, allowing non admin
users that was granted modifyAccount capability to modify SSH keys
of all users, including administrators. But that means such a user
can change the authentication of an existing administrator and then
impersonate the admin to elevate their own account status to that
of an admin.
Rectify it but restricting changing of SSH keys for a user only to
members of administrators group.
Change-Id: If82965391369121b282b969e7072a2bfa3074be9
c055d46280