Fixed `-Label` parsing for the Get-ConfluencePage cmdlet

[claudiospizzi]

Description

Fix issue [#193].

Types of changes

• [X] 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)

Checklist

• [X] My code follows the code style of this project.
• [ ] I have added Pester Tests that describe what my changes should do.
• [ ] I have updated the documentation accordingly.