forked from espressif/esp-idf
Reason: For example, if an url is lack of leading 'http:' by mistake, it causes to http_parser_parse_url() cannot parse http host item, and then pass the null host pointer to _get_host_header(), crash happens. Fix: http added null pointer check now. Closes https://jira.espressif.com:8443/browse/ESPAT-953