test: use ryu version 4.5
test: use ryu version 4.5

Seems that 4.6's bgp parser has a bug.

Signed-off-by: FUJITA Tomonori <93dac1fe9c4b2a3957982200319981492ad4976e@lab.ntt.co.jp>

tamihiro/gobgp,fujita/gobgp,ishidawataru/gobgp,j-kato/gobgp,osrg/gobgp,osrg/gobgp,a16/gobgp,j-kato/gobgp,osrg/gobgp,a16/gobgp,tamihiro/gobgp,ishidawataru/gobgp,a16/gobgp,fujita/gobgp,tamihiro/gobgp,a16/gobgp,fujita/gobgp,a16/gobgp,tamihiro/gobgp,Dipsingh/gobgp,Dipsingh/gobgp,Dipsingh/gobgp,osrg/gobgp,ishidawataru/gobgp,fujita/gobgp,a16/gobgp,a16/gobgp,j-kato/gobgp