Package update quagga in branch sisyphus

The bgp_nlri_parse_vpnv4 function in bgp_mplsvpn.c in the VPNv4 NLRI parser in bgpd in Quagga before 1.0.20160309, when a certain VPNv4 configuration is used, relies on a Labeled-VPN SAFI routes-data length field during a data copy, which allows remote attackers to execute arbitrary code or cause a denial of service (stack-based buffer overflow) via a crafted packet.