fix is_admin still looking at cla_done
    
    previously, even if a user was in the admins group, and had signed the
    FPCA, and were a member of more than one group (CLA+1), they were not
    given access to the admin interface. This was due to the fact that the
    is_admin function was still checking for cla_done rather than
    signed_fpca. THis commit fixes this issue
    
    Signed-off-by: Ryan Lerch <rlerch@redhat.com>