Removing users without group

[czarnymb]

Removing users without group removes additional info like name or email, but not the users.

When I've changed the sql_delete_user_query (52 line in sqlflexibleauthstore.py) from

sql_delete_user_query = Option('account-manager','sql_delete_user_query',"DELETE users.*,membership.* FROM users,membership WHERE membership.userid=users.userid AND users.$username_field$='$username$'",

to

sql_delete_user_query = Option('account-manager','sql_delete_user_query',"DELETE u,m FROM users AS u LEFT JOIN membership AS m ON m.userid=u.userid WHERE u.$username_field$='$username$'",

it worked