s3:utils: Remove call of ads_startup() from net_ads_keytab_create()

s3:utils: Remove call of ads_startup() from net_ads_keytab_create()

Calling ads_startup() is not needed in net_ads_keytab_create.  Keytab
creation code in sync_pw2keytabs() decides if it needs to talk to DC or
not and connects to AD accordingly.

Fixing this, makes the bug below easier to reproduce using
'net ads keytab create'.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15727

Signed-off-by: Pavel Filipenský <pfilipensky@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
Autobuild-User(master): Pavel Filipensky <pfilipensky@samba.org>
Autobuild-Date(master): Mon Mar 10 11:09:29 UTC 2025 on atb-devel-224

(cherry picked from commit 5cadaf91bc96cd2a8e0f6bcbd8a212e86b714180)