User email gets reset upon login

This issue has been filed many times before but each scenario was a bit different. I am hereby describing my situation and the very simple fix I made.

Our LDAP schema doesn't contain an email attribute. As a consequence, the current ldapauth code resets the user's email to NULL upon login. Not nice.

Attached is a fix that simply reads the email from the $user object in case the LDAP email attribute is not present. This way the email won't get erased.