Fix memory issue with large return values in testcases
Fix memory issue with large return values in testcases

Previously http_SUITE:echo_body/1 and http_SUITE:check_raw_status/1
returned large values. Common test would then try to write these to the
logs causing tests to take a long time and use lots of memory.

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