[downloader/http] Fix crash during urlopen caused by missing reason of URLError
[downloader/http] Fix crash during urlopen caused by missing reason of URLError

Tatsh/youtube-dl,rg3/youtube-dl,rg3/youtube-dl,ozburo/youtube-dl,Tatsh/youtube-dl,yan12125/youtube-dl,spvkgn/youtube-dl,yan12125/youtube-dl,spvkgn/youtube-dl,ozburo/youtube-dl