Update Client.php

[khvalov]

Fix for converting $channel / $client to String (if it defined as number) as it is expected by Centrifuge server

[FZambia]

Hello, I understand how user ID can be a number when passing to client functions. But can you explain why these 2 parameters can come as numbers?

[khvalov]

Hi,
You can assign channel name as number (it's valid based on statement https://centrifugal.github.io/centrifugo/server/channels/

"Only ASCII symbols must be used in channel string."

For $client it's kind of confusion around server documentation - (https://centrifugal.github.io/centrifugo/server/private_channels/) - wasn't really clear which client ID supposed to use. I have proposed documentation update with more clarification on ClientID topic.
But here you are right - it's just impossible to get number only Client ID from Centrifuge server