message: Avoid issue where Infura is 1 block behind the chain head, which throws an RPC error: "header not found"
diff: @@ -260,8 +260,15 @@ export default abstract class Layer1ChainWeb3Strategy
  this.cardBalance = new BN(cardBalance);
  }
  - private getErc20Balance(contract: Contract) {
  - return contract.methods.balanceOf(this.walletInfo.firstAddress).call();
  + private async previousBlockNumber(): Promise<number> {
  + // Used to prevent block mismatch errors in infura https://github.com/88mphapp/ng88mph-frontend/issues/55#issuecomment-940414832
  + return (await this.web3!.eth.getBlockNumber()) - 1;
  + }
  +
  + private async getErc20Balance(contract: Contract) {
  + return contract.methods
  + .balanceOf(this.walletInfo.firstAddress)
  + .call({}, await this.previousBlockNumber());
  }
  private async getDefaultTokenBalance() {
  @@ -269,7 +276,7 @@ export default abstract class Layer1ChainWeb3Strategy
  if (this.walletInfo.firstAddress)
  return await this.web3.eth.getBalance(
  this.walletInfo.firstAddress,
  - 'latest'
  + await this.previousBlockNumber()
  );
  else return 0;
  }
  