Typo in header on GUI

[gitname]

The word "System" is misspelled on the GUI:

Relevant source code:
https://github.com/rix0rrr/WindowsPathEditor/blob/master/WindowsPathEditor/MainWindow.xaml#L52

Screenshot of relevant source code:

I didn't open a PR because I don't have any C# development tools installed on this machine and don't want to submit an untested PR.

[gitname]

Someone submitted a PR on this already: #27

[Jaid]

Pull request #27 has been merged now.