Be less confusing in the way we inform the user that logging has started.
Before this patch:
$ src/bitcoind -printtoconsole
2018-03-16T13:07:59Z
2018-03-16T13:07:59Z Bitcoin Core version v0.16.99.0-7be9a9a (release build)
…
After this patch:
$ src/bitcoind -printtoconsole
2018-03-16T13:07:59Z Bitcoin Core version v0.16.99.0-7be9a9a (release build). Logging started.
…