sudo ipa: do not store rules without sudoHost attribute
Unless it is cn=defaults.
This was already fixed in LDAP provider with:
47ad0778be72994a2294b2e73cc5c670be6811a7
Resolves:
https://pagure.io/SSSD/sssd/issue/3980
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>