To turn off system sound by default

[meets2tarun]

Short description

I have:

• There is a corresponding issue for this pull request.
• Mentioned the Issue number in the pull request commit message Fixes #<number> commit message
  Configuration needed in the LXQt version #88
  This PR will take care to turn off the system sound in the LXQt version of meilix and this is achieved using the config file of LXQt which is copied in the skel folder

For the reviewers

I have:

• Reviewed this pull request by an authorized contributor.
• The reviewer is assigned to the pull request.

[tabesin]

Please ensure proper naming of the PR and the commit message

[mariobehling]

Please resolve conflicts.