Get appimaged from its new location

[probonopd]

https://github.com/AppImage/appimaged/releases/tag/continuous thanks to AppImage/AppImageKit#656

[TheAssassin]

wget -qO- https://api.github.com/repos/appimage/appimaged/releases | grep browser_download | grep ".deb" | head -n1 | cut -d'"' -f4