[Linux] Fix "Unexpected argument '&'" error when trying to open URL

[NotHyper-474]

Fixes the background thingie not being passed properly to the command line due to how Sys works, which causes an error and prevents the link from being opened

Could be something with my system for all I know, not sure if being on Ubuntu WSL2 changes how the command behaves.
If anyone else also compiles in Linux (no WSL) please confirm if this error happens to you too.

Edit: I tested this through native Ubuntu and also got the same error, so not related to WSL, unless it's related to Ubuntu in general.
Edit 2: This error is caused by how Haxe's Sys.command appends the arguments to the console, encasing them with single quotes. So the original code would cause the command to be xdg-open 'https:/link.here' '&' which makes xdg think that & is an argument, so not related to any Linux distro.

[gamerbross]

using string interpolation should be more readable

Sys.command('/usr/bin/xdg-open $targetUrl &');

[NotHyper-474]

Alright, thanks, gonna do that now.

[ninjamuffin99]

if someone can show/record some before/after of this change, that would be very helpful :)
also im linux noob still, this is consistent across distros ? i was always curious about that command...

[NotHyper-474]

xdg-open is part of the xdg-utils package, which generally is installed by default in distros with a desktop manager, so it's not guaranteed to work in every single distro, but there doesn't seem to exist a better alternative.

And here's the before and after, tested in Kali Linux (WSL)

before.mp4

after.mp4

[ninjamuffin99]

very nice !