xdg-settings: default-url-scheme-handler not implemented for xfce

[probonopd]

Bug A clear and concise description of what the bug is.

To Reproduce Steps to reproduce the behavior:

1. Try to run LBRY_0.43.3.AppImage
2. See error

Expected behavior

The application runs

Screenshots

System Configuration

• LBRY Daemon version: LBRY_0.43.3.AppImage
• LBRY App version: LBRY_0.43.3.AppImage
• LBRY Installation ID: ?
• Operating system: Xubuntu bionic Live ISO

me@host:~$ curl 'http://localhost:5279' --data '{"method":"version"}'
{
  "jsonrpc": "2.0",
  "result": {
    "build": "release",
    "desktop": "XFCE",
    "distro": {
      "codename": "bionic",
      "id": "ubuntu",
      "like": "debian",
      "version": "18.04",
      "version_parts": {
        "build_number": "",
        "major": "18",
        "minor": "04"
      }
    },
    "lbrynet_version": "0.63.0",
    "os_release": "5.3.0-28-generic",
    "os_system": "Linux",
    "platform": "Linux-5.3.0-28-generic-x86_64-with-Ubuntu-18.04-bionic",
    "processor": "x86_64",
    "python_version": "3.7.6",
    "version": "0.63.0"
  }
}

[probonopd]

0.45.2 also does not run:

me@host:~$ '/home/me/Downloads/LBRY_0.45.2.AppImage'
Starting SDK
Trace/breakpoint trap

[tzarebczan]

Thanks for filing. The latest should be working - can you try it again?

[probonopd]

me@host:~$ Downloads/LBRY_0.46.0-rc.1.AppImage 
Starting SDK
Trace/breakpoint trap