message: Log in GELF 1.1 format, with unstringified numbers.
diff: @@ -150,7 +150,7 @@ namespace fc
  if (!context.get_task_name().empty())
  gelf_message["_task_name"] = context.get_task_name();
  - string gelf_message_as_string = json::to_string(gelf_message);
  + string gelf_message_as_string = json::to_string(gelf_message, json::legacy_generator); // GELF 1.1 specifies unstringified numbers
  //unsigned uncompressed_size = gelf_message_as_string.size();
  gelf_message_as_string = zlib_compress(gelf_message_as_string);
  