kdc: Fix Samba's KDC to only change the principal in the right cases
If we are set to canonicalize, we get back the fixed UPPER
case realm, and the real username (ie matching LDAP
samAccountName)
Otherwise, if we are set to enterprise, we
get back the whole principal as-sent
Finally, if we are not set to canonicalize, we get back the
fixed UPPER case realm, but the as-sent username
Signed-off-by: Garming Sam <garming@catalyst.net.nz>
Pair-programmed-with: Garming Sam <garming@catalyst.net.nz>
Signed-off-by: Andrew Bartlett <abartlet@samba.org>