UTILS: More restrictive permissions in domain_info
    
    There are two occurances of creating temp. file under SSS_DFL_X_UMASK
    permissions which enable possibility to grant executable permission.
    After writting to those temp. files, they are renamed and they
    get 0644 permissions. So SSS_DFL_UMASK is good enough fot this case.
    
    Resolves:
    https://fedorahosted.org/sssd/ticket/2424
    
    Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>