return -1 for failed query instead of exit(1)
return -1 for failed query instead of exit(1)

embeddedmz/restclient-cpp,benjam60/restclient-cpp,seem-sky/restclient-cpp,69736c616d/restclient-cpp,benjam60/restclient-cpp,embeddedmz/restclient-cpp,benjam60/restclient-cpp,seem-sky/restclient-cpp,benjam60/restclient-cpp,seem-sky/restclient-cpp,69736c616d/restclient-cpp,seem-sky/restclient-cpp,69736c616d/restclient-cpp,mrtazz/restclient-cpp,mrtazz/restclient-cpp,69736c616d/restclient-cpp