/usr/include/php/20170718/ is in php-http 3.1.0+2.6.0-4build8.
This file is owned by root:root, with mode 0o755.
..
/usr/include/php/20170718/ext/
/usr/include/php/20170718/ext/http/
/usr/include/php/20170718/ext/http/php_http.h
/usr/include/php/20170718/ext/http/php_http_api.h
/usr/include/php/20170718/ext/http/php_http_buffer.h
/usr/include/php/20170718/ext/http/php_http_client.h
/usr/include/php/20170718/ext/http/php_http_client_curl.h
/usr/include/php/20170718/ext/http/php_http_client_curl_event.h
/usr/include/php/20170718/ext/http/php_http_client_curl_user.h
/usr/include/php/20170718/ext/http/php_http_client_request.h
/usr/include/php/20170718/ext/http/php_http_client_response.h
/usr/include/php/20170718/ext/http/php_http_cookie.h
/usr/include/php/20170718/ext/http/php_http_curl.h
/usr/include/php/20170718/ext/http/php_http_encoding.h
/usr/include/php/20170718/ext/http/php_http_env.h
/usr/include/php/20170718/ext/http/php_http_env_request.h
/usr/include/php/20170718/ext/http/php_http_env_response.h
/usr/include/php/20170718/ext/http/php_http_etag.h
/usr/include/php/20170718/ext/http/php_http_exception.h
/usr/include/php/20170718/ext/http/php_http_filter.h
/usr/include/php/20170718/ext/http/php_http_header.h
/usr/include/php/20170718/ext/http/php_http_header_parser.h
/usr/include/php/20170718/ext/http/php_http_info.h
/usr/include/php/20170718/ext/http/php_http_message.h
/usr/include/php/20170718/ext/http/php_http_message_body.h
/usr/include/php/20170718/ext/http/php_http_message_parser.h
/usr/include/php/20170718/ext/http/php_http_misc.h
/usr/include/php/20170718/ext/http/php_http_negotiate.h
/usr/include/php/20170718/ext/http/php_http_object.h
/usr/include/php/20170718/ext/http/php_http_options.h
/usr/include/php/20170718/ext/http/php_http_params.h
/usr/include/php/20170718/ext/http/php_http_querystring.h
/usr/include/php/20170718/ext/http/php_http_response_codes.h
/usr/include/php/20170718/ext/http/php_http_url.h
/usr/include/php/20170718/ext/http/php_http_utf8.h
/usr/include/php/20170718/ext/http/php_http_version.h