HTTP code 404 as potentially_down

[spirillen]

Setting a HTTP code 404 as potential down seems to be on the edge, as this just as often might be considered as a response code depending on CROSS origin and software that queried, and a lot of other arguments.

I suggest to avoid FalseNegatives it is moved to the potentially_up, this is suggestion to the rationale of rather one to many records in the blacklist. It is after all only a few bits per record.

[spirillen]

Just noticed that http code 444 (Nginx no response code) are missing from the up list