mattermost-desktop: Add silentArg ALLUSERS=1

[staeglis]

Description

Add silentArg ALLUSERS=1 for package mattermost-desktop

Motivation and Context

If silentArg ALLUSERS=1 is not set the package is installed as user only

How Has this Been Tested?

Only tested via installing the msi manually

Screenshot (if appropriate, usually isn't needed):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Migrated package (a package has been migrated from another repository)

Checklist:

• My code follows the code style of this repository.
• My change requires a change to documentation (this usually means the notes in the description of a package).
• I have updated the documentation accordingly (this usually means the notes in the description of a package).
• I have updated the package description and it is less than 4000 characters.
• All files are up to date with the latest Contributing Guidelines
• The added/modified package passed install/uninstall in the Chocolatey Test Environment(https://github.com/chocolatey-community/chocolatey-test-environment/). Note that we don't support the use of any other environment.
• The changes only affect a single package (not including meta package).

Original Location

• Original Repository
• Open Issues Add the different issues underneath, and tick those that are fixed in this PR
  • Issue 1 link
  • Issue 2 Link
• Include the link to the opened PR that removes the package from the original location
• The migration guidelines have been followed

[AppVeyorBot]

❌ Package verification failed, please review the Appveyor Logs and the provided Artifacts before requesting a human reviewer to take a look.

[AppVeyorBot]

✅ Package verification completed without issues. PR is now pending human review

[TheCakeIsNaOH]

All package code changes should be tested in the Chocolatey Test Environment as per the PR checklist.