Drop years from Red Hat copyright
Drop years from Red Hat copyright

Red Hat's latest copyright guidance says to simply use "Copyright Red
Hat". Switch to that in ./git-publish to eliminate the need to update
the year, which is easily forgotten.

Signed-off-by: Stefan Hajnoczi <484520986196e4a799496429ce8a499eb6488adb@gmail.com>

stefanha/git-publish,stefanha/git-publish