Fix issue if a file leading trivia starts with the copyright header

[AndyGerlicher]

This should fix issues causing the file header to be messed up when the copyright header is already at the top of the file. See Issue #96 for details.

[dnfclas]

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[dnfclas]

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[krwq]

LGTM 👍

[jaredpar]

👍

Thanks for contributing that fix!