Update build_host_setup_arch.sh (#459)
Update build_host_setup_arch.sh (#459)

Add --needed flag to not reinstall all packages in the list (just install the ones needed)
MycroftAI/mycroft-core,linuxipho/mycroft-core,MycroftAI/mycroft-core,aatchison/mycroft-core,aatchison/mycroft-core,linuxipho/mycroft-core,forslund/mycroft-core,forslund/mycroft-core,Dark5ide/mycroft-core,Dark5ide/mycroft-core