fixed credential warning message to say warning not error
fixed credential warning message to say warning not error

Fixes #1387

vcgato29/heroku,greeca0204/heroku,gregburek/heroku,dickeyxxx/heroku,gregburek/heroku,Faisalawanisee/heroku,sancopanco/heroku,macedo/heroku,greeca0204/heroku,duypq94/heroku,dickeyxxx/heroku,Faisalawanisee/heroku,macedo/heroku,vcgato29/heroku,duypq94/heroku,rkh/heroku,rkh/heroku,gregburek/heroku,duypq94/heroku,macedo/heroku,vcgato29/heroku,sancopanco/heroku,dickeyxxx/heroku,sancopanco/heroku,rkh/heroku,Faisalawanisee/heroku,greeca0204/heroku