New usage message to fix some short option issues
New usage message to fix some short option issues

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