Merge pull request #4419 from SvenDowideit/tweak-DCO-hook-for-windows

Fix newlines echoing in DCO git hook contrib script

contrib/prepare-commit-msg.hook

@@ -4,4 +4,4 @@
 #
 GH_USER=$(git config --get github.user)
 SOB=$(git var GIT_AUTHOR_IDENT | sed -n "s/^\(.*>\).*$/Docker-DCO-1.1-Signed-off-by: \1 \(github: $GH_USER\)/p")
-grep -qs "^$SOB" "$1" || echo "\n$SOB" >> "$1"
+grep -qs "^$SOB" "$1" || echo -e "\n$SOB" >> "$1"