Fix buildavalancheproof RPC with bitcoin-cli
Summary: The sequence and expiration params need to be converted from string.
Test Plan:
./src/bitcoin-cli buildavalancheproof 11 12
030b4c866585dd868a9d62348a9cd008d6a312937048fff31670e7e920cfc7a744
'[{"txid":
"12b004fff7f4b69ef8650e767f18f11ede158148b425660723b9f9a66e61f747",
"vout": 0, "amount": 10, "height": 100, "privatekey":
"030b4c866585dd868a9d62348a9cd008d6a312937048fff31670e7e920cfc7a744"}]'Returns Invalid private key
./test/functional/test_runner.py abc_p2p_avalanche
Reviewers: #bitcoin_abc, deadalnix
Reviewed By: #bitcoin_abc, deadalnix
Differential Revision: https://reviews.bitcoinabc.org/D8556