RPC getnetworkinfo: export local node's client sub-version string
RPC getnetworkinfo: export local node's client sub-version string

Rebased-from: ff36cbe8d010bd17d7d8fe2ba9293864833884e2

litecoin-project/bitcoinomg,litecoin-project/bitcoinomg,litecoin-project/bitcoinomg,litecoin-project/bitcoinomg