[Screeninvader] ScreenInvader partial outage

[Amir]

YouTube and youtube-dl are intensifying their arms race it seems. in the 
last week sometimes the screeninvader worked nicely (youtube-dl is 
updated every 10 min) and sometimes most of the videos wouldn't play. 
Behavior virtually changes with every youtube-dl update. Also it seems 
now that Youtube switched to providing the videos unmuxed which means 
there are two files each for video and audio.
And finally thumbnail loading for videos broke too which means i also 
have to update searx (which provides meta search on the SI page)

your friendly and devoted maintainer