new-chat-dialog: Simplify checking if a number is valid
We already have an API to check if a number is valid. Let's use that and remove thus not used method
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this page for instructions on how to get full permissions. Sorry for the inconvenience.
We already have an API to check if a number is valid. Let's use that and remove thus not used method