Add http_connection to json logging (for Connection header)

Author: itskingori

config/log.conf

@@ -7,6 +7,7 @@ log_format main_json escape=json
   '{'
     '"body_bytes_sent":"$body_bytes_sent",'
     '"host":"$host",'
+    '"http_connection":"$http_connection",'
     '"http_referrer":"$http_referer",'
     '"http_user_agent":"$http_user_agent",'
     '"http_x_forwarded_for":"$http_x_forwarded_for",'