fix sample code in link

Author: pterk

README.md

@@ -64,7 +64,7 @@ $expiration = (new DateTime())->getTimestamp() + 3600;
 $token = $client->createToken("bob-1", $expiration);
 ```
 
-Set location. Tell the client where your app is [hosted](https://getstream.io/chat/docs/multi_region/?language=kotlin&q=locations).
+Set location. Tell the client where your app is [hosted](https://getstream.io/chat/docs/multi_region/?language=php&q=locations).
 
 ```php