git: adapted alias 'tree'

setup

@@ -26,7 +26,7 @@ git config --global alias.jingle "!git fetch && git tree"
 git config --global alias.pick "cherry-pick"
 git config --global alias.status-tracked "status --untracked-files=no"
 git config --global alias.timestamp 'show --no-patch --format="%at"'
-git config --global alias.tree "log --graph --abbrev-commit --decorate --format=format:'%C(red)%h%C(reset)%C(bold red)%d%C(reset) %C(dim green)(%ar)%C(reset) %C(dim white)%s%C(reset) %C(bold black)(%an, %ad)%C(reset)' --all --date=short"
+git config --global alias.tree "log --graph --abbrev-commit --decorate --format=format:'%C(red)%h%C(reset)%C(bold red)%d%C(reset) %C(dim green)(%ar)%C(reset) %C(dim white)%s%C(reset) %C(bold black)(%an, %ai)%C(reset)' --all --date=short"
 
 # filters
 git config --global filter.strip-html-comments.clean 'strip-html-comments'