Update dependency exabgp to v4.2.6
Update dependency exabgp to v4.2.6

trungdtbk/faucet,REANNZ/faucet,gizmoguy/faucet,mwutzke/faucet,shivarammysore/faucet,faucetsdn/faucet,trungdtbk/faucet,mwutzke/faucet,shivarammysore/faucet,gizmoguy/faucet,faucetsdn/faucet,anarkiwi/faucet,REANNZ/faucet,anarkiwi/faucet