several bugfixes

- fix undefined method 'WriteKdbvalue' (bnc#885833)
- add Kerberos dialog to Replication Master Setup (bnc#885829)
- update kerberos stash when changing LDAP password (bnc#865296)
i can be only boolean so simple `AuthServer.WriteKerberosLdapDBvalue("kdb_sscope", i ? "sub" : "one")` is enough