refactor the building of the User-Agent string
refactor the building of the User-Agent string

proneoas/httpful,cybercircuits/httpful,claimsmall/httpful,quafzi/httpful,mojaray2k/httpful,infame-io/httpful,barracudanetworks/httpful,nategood/httpful,myorb/httpful,siwinski/httpful