BGPSpeaker: Fix capability check when MP-BGP not supported
BGPSpeaker: Fix capability check when MP-BGP not supported

Currently, BGPSpeaker skips sending the Update messages with an
IPv4/IPv6 prefix when the peer does not support MP-BGP.
This patch fixes capability check in order to send IP prefix when
MP-BGP not suppored by the peer.

Signed-off-by: IWASE Yusuke <bb80e84cc9f5a8f01385872ee89032beb5d4eba7@gmail.com>
Signed-off-by: FUJITA Tomonori <93dac1fe9c4b2a3957982200319981492ad4976e@lab.ntt.co.jp>

pichuang/ryu,iwaseyusuke/ryu,gareging/SDN_Framework,TakeshiTseng/ryu,fkakuma/ryu,fkakuma/ryu,TakeshiTseng/ryu,shinpeimuraoka/ryu,fujita/ryu,fujita/ryu,iwaseyusuke/ryu,osrg/ryu,fujita/ryu,fujita/ryu,shinpeimuraoka/ryu,osrg/ryu,pichuang/ryu,TakeshiTseng/ryu,shinpeimuraoka/ryu,iwaseyusuke/ryu,lagopus/ryu-lagopus-ext,TakeshiTseng/ryu,osrg/ryu,iwaseyusuke/ryu,fkakuma/ryu,pichuang/ryu,lagopus/ryu-lagopus-ext,iwaseyusuke/ryu,fkakuma/ryu,osrg/ryu,lagopus/ryu-lagopus-ext,gareging/SDN_Framework,osrg/ryu,TakeshiTseng/ryu,shinpeimuraoka/ryu,fkakuma/ryu,shinpeimuraoka/ryu,fujita/ryu,pichuang/ryu,lagopus/ryu-lagopus-ext,pichuang/ryu,gareging/SDN_Framework,lagopus/ryu-lagopus-ext,gareging/SDN_Framework,gareging/SDN_Framework