Fix build with BUILD_SHARED_LIBS on.
Fix build with BUILD_SHARED_LIBS on.

PowerOlive/badvpn,tempbottle/badvpn,LazyZhu/badvpn,tempbottle/badvpn,Git-Host/badvpn,tempbottle/badvpn,binondord/badvpn,linfengfeiye/badvpn,Git-Host/badvpn,Git-Host/badvpn,LazyZhu/badvpn,binondord/badvpn,Git-Host/badvpn,linfengfeiye/badvpn,binondord/badvpn,linfengfeiye/badvpn,linfengfeiye/badvpn,Git-Host/badvpn,PowerOlive/badvpn,PowerOlive/badvpn,PowerOlive/badvpn,tempbottle/badvpn,binondord/badvpn,tempbottle/badvpn,PowerOlive/badvpn,linfengfeiye/badvpn,binondord/badvpn,LazyZhu/badvpn,LazyZhu/badvpn,LazyZhu/badvpn