nostr-php : * add backwards compatibility in the __construct() of relay for the $message argument which was used in version < 1.2.4

* fix WebsocketClient response (message) which returned an array instead of a string for the json_decode function

https://github.com/nostrver-se/nostr-php/commit/2fe0a631af837043f47223d46abb816c946c57e0