Kraken: Fix WS Auth endpoints not re-enabled (#1334)

When Kraken has a disconnect or failure that sets SetCanUseAuthenticatedEndpoints(false),
it's never re-enabled when the websocket is reconnected
That means all subsequent requests would fall back to rest

exchanges/kraken/kraken_websocket.go

@@ -117,6 +117,7 @@ func (k *Kraken) WsConnect() error {
 					k.Name,
 					err)
 			} else {
+				k.Websocket.SetCanUseAuthenticatedEndpoints(true)
 				k.Websocket.Wg.Add(1)
 				go k.wsFunnelConnectionData(k.Websocket.AuthConn, comms)
 				err = k.wsAuthPingHandler()