libretro-fetch Chokes on Dead Citra Repos

[ChthonVII]

Basically the title. libretro-fetch is trying to fetch stuff from dead citra repos. This causes the script to repeatedly stop, prompt for a username, prompt for a password, fail to download the citra stuff, then continue on. In an ideal world, the missing items would be hosted somewhere, and libretro-fetch should be pointed at them. Barring that, the citra cores should be skipped by libretro-fetch.

[jonian]

I have a submitted libretro/citra#130 that replaces the dead repos.

[dxgldotorg]

This issue also occurs to the automatic build system, which on a daily basis posts an error messge on Discord.