delete unnessesary use of test_client in test:json_passthrough

test/test_sams_proxy.py

@@ -187,7 +187,6 @@ class TestSAMSHub(unittest.TestCase):
     thProxyApp = FlaskInThread(proxyApp, host="localhost", port=5000)
     thProxyApp.start()
     time.sleep(1)
-    with proxyApp.test_client(self) as client:
     res = requests.post(url='http://localhost:5000/proxy/passthrough',
       json={'g':'bar'})
     resDict = json.loads(res.content.decode('utf-8'))