Fix build on Darwin
Fix build on Darwin

Signed-off-by: Jussi Virtanen <2a7e40f91a3be32dfb7e35af6e476a252ebdb4f3@gmail.com>

Bitcoinsulting/libtrading,penberg/libtrading,fengzhyuan/libtrading,fengzhyuan/libtrading,svdev/libtrading,libtrading/libtrading,divaykin/libtrading,femtotrader/libtrading,libtrading/libtrading,mstanichenko/libtrading,jvirtanen/libtrading,divaykin/libtrading,svdev/libtrading,Bitcoinsulting/libtrading,femtotrader/libtrading,penberg/libtrading,etoestja/libtrading,mstanichenko/libtrading,jvirtanen/libtrading,etoestja/libtrading,NunoEdgarGub1/libtrading,NunoEdgarGub1/libtrading