Call-time pass-by-reference has been deprecated

I encountered these errors after installing Contact Attach on my 6.8 install...

Warning: Call-time pass-by-reference has been deprecated; If you would like to pass it by reference, modify the declaration of [runtime function name](). If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file in
/sites/all/modules/contact_attach/contact_attach.module on line 155

Warning: Call-time pass-by-reference has been deprecated; If you would like to pass it by reference, modify the declaration of [runtime function name](). If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file in
/sites/all/modules/contact_attach/contact_attach.module on line 223

I looked around at some other modules that once had similar errors. Most of the fixes I saw were typo-based. so in contact_attach.module, I eliminated the "&" signs before $form_state x 4, as seen below...

Line 154:

function contact_attach_contact_mail_page_validate($form, &$form_state) {
  _contact_attach_upload_validate($form, &$form_state);
}  //  End of contact_attach_contact_mail_page_validate().

Line 222:

function contact_attach_contact_mail_user_validate($form, &$form_state) {
  _contact_attach_upload_validate($form, &$form_state);
}  //  End of contact_attach_contact_mail_user_validate().

Once I changed those (4) "&$form_state" to "$form_state", the errors went away.