Fixes #2717. Label not display fully when resizing terminal.

[BDisp]

Fixes #2717 - The negative location must be take on consideration to ignore his content.

Pull Request checklist:

• I've named my PR in the form of "Fixes #issue. Terse description."
• My code follows the style guidelines of Terminal.Gui - if you use Visual Studio, hit CTRL-K-D to automatically reformat your files before committing.
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