Fix deployment of Samba AD DC with MIT Kerberos
When DES encryption is not supported in MIT Kerberos, deployment of
Samba AD DC fails with
"ERROR(ldb): uncaught exception - setup_kerberos_keys: generation of a
des-cbc-md5 key failed: Bad encryption type"
Fix it by not using DES encryption types in MIT build.
Resolves #1757071
(cherry picked from commit 03a27a2599d9b8e7fd9ed38a9f47277c49575968)