There is another nuisance in config.html. Line 27 reads
…“stylesheet” href="//fonts.googleapis.com/css?family=Lato:400,300,700,900…
which means every time you access webconf page some data fetched from fonts.googleapis.com. When there no internet connection available, then browser just sits and waits until request times out. I tried to comment this line out and can’t see difference in page rendering style, just a bit faster.