Need to change the default cap on transaction fee (1 ether) that can be sent via the RPC APIs

Encountered the error `“Failed to submit mined result         shard=0 block=7,350,229 error="tx fee (164.48 ether) exceeds the configured cap (1.00 ether)”` while submitting the EthStorage mining transaction

Since we’re using QKC instead of ETH to measure the gas fee, we may need to increase the default cap for --rpc.txfeecap from 1 to 1000, as suggested by @qizhou.