Revert "PasswordTool: Ignore entries which don't come from ERP5LoginUserManager"

This reverts commit 716493d6.

Rationale: If there are multiple entries on the list, it means that the
  acl_users are miss-configured, which is a problem. Since, by changing
  the password on one entry the other (zodb_users for example), can still
  rely on the previous value, making login fail anyway.

  So we drop this workarround.