Improve stabilitiy of hafah_functional_tests

Made correction in function send_request_to_hafah

Repaired problem description: When hafah send get_transaction request with incorrect transaction id is return exception. Python function, Which sending hafah requests does not support such a case and not working correct. Normally, this function tries to send 5 requests before return exception, but in get transaction send request only once. This is the reason Why this exception appear from time to time.