Improve generate_etag return value description
Improve generate_etag return value description

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