"getnetworkhashps" with defaults was yielding "0", the hashrate is not 0.

This was broken in 4c6d41b8b653ef90639b1a32f6aab0bb1cef90c5.
Merge pull request #3474

aec55a0 "getnetworkhashps" with defaults was yielding "0", the hashrate is not 0. (Gregory Maxwell)