added exception message in retry_handler

Author: PraneethChandraThota

socketlabs/injectionapi/core/retryhandler.py

@@ -46,7 +46,7 @@ def send(self, body):
                 response = self.__http_client.send_request(body)
 
                 if response.status in self.ErrorStatusCodes:
-                    raise HTTPException
+                    raise HTTPException("HttpStatusCode: {0}. Response contains server error.".format(response.status))
 
                 data = response.read().decode("utf-8")
                 response_code = response.status