LICENSE_HEADER.md contains a link to corp url

[filmaj]

74:To learn more about Adobe copyright, checkout our [Copyrights documentation](https://inside.corp.adobe.com/intellectual-property/copyrights.html#jcr-content_par_tab_Adobe-Copyright-Notices).

[frunkad]

Could do it as my first PR. What shall be more appropriate instead of the URL? @filmaj