package/dovecot-pigeonhole: bump version to 0.5.6
Release notes:
https://dovecot.org/pipermail/dovecot-news/2019-April/000411.html
Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 03a78e347077ad5c9d1c85349aee940aae0d9af8)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>