python:gp: Improve working of log messages to avoid confusion

python:gp: Improve working of log messages to avoid confusion

We should not use the word "Failed". We are totally fine if we can't
connect to NDES in the meantime. This logs:

Try to get root or server certificates.
Unable to install root certificates (requires NDES).
Installing the server certificate only.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15559

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: David Mulder <dmulder@samba.org>
Reviewed-by: Pavel Filipenský <pfilipensky@samba.org>
Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Mon Jan 29 10:37:29 UTC 2024 on atb-devel-224