Update cowboy2_adapter.ex (#3889)
Update cowboy2_adapter.ex (#3889)

Close #3888

Ref https://github.com/phoenixframework/phoenix/blob/33ba200025afcf79f854dc6bc11bd9e27535056c/lib/phoenix/endpoint/cowboy2_adapter.ex#L69-L73
0x00evil/phoenix,optikfluffel/phoenix,optikfluffel/phoenix,0x00evil/phoenix,nshafer/phoenix,rafbgarcia/phoenix,michalmuskala/phoenix,eksperimental/phoenix,phoenixframework/phoenix,phoenixframework/phoenix,eksperimental/phoenix,nshafer/phoenix,0x00evil/phoenix,optikfluffel/phoenix,michalmuskala/phoenix,rafbgarcia/phoenix,phoenixframework/phoenix,nshafer/phoenix,rafbgarcia/phoenix