fix error introduced in pushed patch

Hi, A friend of mine just complained about an issue he had with upstream notmuch python that is due to my recent reformating of Message.__str__. This patch fixes it. Sorry for the inconveniences, /p

fix error introduced in pushed patch

Hi, A friend of mine just complained about an issue he had with upstream notmuch python that is due to my recent reformating of Message.__str__. This patch fixes it. Sorry for the inconveniences, /p ___ notmuch mailing list notmuch@notmuchmail.org