BeneficiaryPublicKey return undefined in BlockInfo.

[AnthonyLaw]

1. Expected behavior and actual behavior.
   BeneficiaryPublicKey should return publicKey.

2. Steps to reproduce the problem.
   Network: http://api-xym-3-01.us-west-2.nemtech.network:3000/block/10000
   BlockHttp.getBlockByHeight(10000)
   BeneficiaryPublicKey show undefined in BlockInfo

3. Specifications like the version of the project, operating system, or hardware.
   nem2-sdk: "0.16.5"