Revert "Set CHANGES.txt git merge driver to union"
Revert "Set CHANGES.txt git merge driver to union"

This reverts commit ce5037b73c4d1d6dd6bcc752a9f968adf2a3947a.

Instead of removing the hassle with merge conflicts on the CHANGES.txt
file it lead to a couple of mistakes because it merged the CHANGES.txt
incorrectly without merge conflict.

crate/crate,EvilMcJerkface/crate,crate/crate,crate/crate,EvilMcJerkface/crate,EvilMcJerkface/crate