[SSSD] [PATCH] krb5-child: add revert_changepw_options()

[Sumit Bose]

Hi,

a recent patch unified the usage of the krb5_get_init_creds_opt options
to make sure the same set of FAST related options are uses for
authentication and password changes. Before changing the password some
options were set to special values but were not reverted before
requesting a new TGT with the new password. As a result the new TGT will
have some unexpected options set or the request might even fail.

This patch set resets the password change related option to their
original values before requesting the new TGT.

The first two patches are just refactorings which are required to keep
the third patch simple.

bye,
Sumit