Set number of CPUs on OSX build (@skaht).
Set number of CPUs on OSX build (@skaht).

RojavaCrypto/libbitcoin-server,tuomassiren/libbitcoin-server,tuomassiren/libbitcoin-server,RojavaCrypto/libbitcoin-server,RojavaCrypto/libbitcoin-server,tuomassiren/libbitcoin-server