Thank you ! But they haven't updated my address as I travelled to my home country, although I have submitted webform on August 10 to change address. So I have to communicate that with them. In the RFV letter, they say use webform
http://www.cic.gc.ca/english/contacts/web-form.asp to inform London IRCC office, but with that webform we can't choose office in Canada, how can we inform a specific office in Canada with webform ? I sent an email to London office (the email address they asked for ADR), will see if they reply my email.