fix: do not log the error in the log informing retries have stop

This would prevent polluting the log. The caller would be able to create
its own log with the cause if wanted.

gravitee-exchange-connector/gravitee-exchange-connector-websocket/src/main/java/io/gravitee/exchange/connector/websocket/WebSocketExchangeConnector.java

@@ -92,7 +92,7 @@ public Completable initialize() {
                     if (err instanceof WebSocketConnectorException connectorException && connectorException.isRetryable()) {
                         return Flowable.timer(5000, TimeUnit.MILLISECONDS);
                     }
-                    log.error("Unable to connect to Exchange Connect Endpoint, stop retrying.", err);
+                    log.error("Unable to connect to Exchange Connect Endpoint, stop retrying.");
                     return Flowable.error(err);
                 })
             );