Simplify LDAP schemas.

Since 96fc5ae69bc0d1c0037e2223f0dccfcf6347abed we no longer
require the person schemas. This greatly simplifies LDAP
processing and reduces the possiblitity of bugs by choosing
person/account incorrectly.

Change-Id: I8208f163deee41679a61a16e9895ee3dac834248