[HTML] Informatinal and error pages of "I2Pd HTTP proxy" to be adapted to Semitic scriptures

Arabic, Farsi, Urdu, et cetera.

Proxy error: Host not found

http://suku.i2p

`dir="rtl"` in tag "body" or "html" should suffice.

Experimented with.

https://greasyfork.org/scripts/490275-switch-page-direction

https://greasyfork.org/scripts/467249-switch-page-direction