fix bug with large ASN4 (value) in as-path
fix bug with large ASN4 (value) in as-path

earies/exabgp,PowerDNS/exabgp,benagricola/exabgp,fugitifduck/exabgp,fugitifduck/exabgp,blablacar/exabgp,chrisy/exabgp,fugitifduck/exabgp,benagricola/exabgp,earies/exabgp,lochiiconnectivity/exabgp,dneiter/exabgp,earies/exabgp,chrisy/exabgp,dneiter/exabgp,blablacar/exabgp,chrisy/exabgp,dneiter/exabgp,benagricola/exabgp,PowerDNS/exabgp,lochiiconnectivity/exabgp,blablacar/exabgp,PowerDNS/exabgp,lochiiconnectivity/exabgp