Check that WS connection is open before closing it on failed. Fixes #3346

Summary: Check that the WS state is set to OPEN before trying to close it when the ```websocketFailed``` event fires. Otherwise the app throws an error at the Android level.

Fixes #3346
Closes #3347

Reviewed By: @​svcscm

Differential Revision: D2535807

Pulled By: @mkonicek

fb-gh-sync-id: bb70c551ea2e582cfaa80139a265dbbca6d990d2

Author: yzarubin

Libraries/WebSocket/WebSocket.js

@@ -115,7 +115,7 @@ class WebSocket extends WebSocketBase {
         this.onerror && this.onerror(event);
         this.dispatchEvent(event);
         this._unregisterEvents();
-        this._closeWebSocket(id);
+        this.readyState === this.OPEN && this._closeWebSocket(id);
       })
     ];
   }