(autohotkey) add square brackets to au_SearchReplace nuspec

[kilobyte1024]

Description

I'm hoping this package will be the new example referenced from chocolatey-au. Even if it's not, having a locked installer package version seems to be best practice for metapackages going forward.

Motivation and Context

For more on this, see chocolatey-au issue #69

How Has this Been Tested?

None

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

None

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).

[AppVeyorBot]

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