eth_getTransactionReceipt fails for cancelled transaction

[s-medvedev]

Symptom:
eth_getTransactionReceipt fails with error message: 'NoneType' object is not iterable

STR:
Pass OpenZeppelin tests and analyze results for requests in the proxy log

Actual result:
Some of eth_call requests fails with "error": {"code": -32000, "message": "'NoneType' object is not iterable"}

Expected result:
Successful execution

Additional info:
The proxy log contains:

Traceback (most recent call last):
  File "/opt/proxy/plugin/solana_rest_api.py", line 577, in process_request
    response['result'] = method(*request['params'])
  File "/opt/proxy/plugin/solana_rest_api.py", line 307, in eth_getTransactionReceipt
    for log in logs:
TypeError: 'NoneType' object is not iterable