Add cowboy_websocket:close_code/0
Add cowboy_websocket:close_code/0

Also fixes a warning.

layerhq/cowboy,imdeps/cowboy,nviennot/cowboy,cad627/cowboy,piboye/cowboy,MSch/cowboy,rbalint/pkg-erlang-cowboy,kivra/cowboy,bsmr-erlang/cowboy,piboye/cowboy,K2InformaticsGmbH/cowboy,venkateshreddy/cowboy,callsign-core/cowboy_hybi00,callsign-core/cowboy_hybi00,heroku/cowboyku,binarin/cowboy,CrankWheel/cowboy,binarin/cowboy,ferd/cowboyku,bobos/ecweb,yangchengjian/cowboy,heroku/cowboy,Reimerei/cowboy,lpgauth/cowboy,rabbitmq/cowboy,LineMetrics/cowboy,cad627/cowboy,turtleDeng/cowboy,unisontech/cowboy,paulperegud/cowboy,manastech/cowboy,unisontech/cowboy,acrispin/cowboy,essen/cowboy,odo/cowboy,layerhq/cowboy,lpgauth/cowboy,LineMetrics/cowboy,dangjun625/cowboy,pap/cowboy,noname007/cowboy,grahamrhay/cowboy,linearregression/cowboyku,omusico/cowboy,LineMetrics/cowboy,hairyhum/cowboy,heroku/cowboy,manastech/cowboy,276361270/cowboy,ninenines/cowboy,essen/cowboy,sile/cowboy,yangchengjian/cowboy