testing/hwatch: upgrade to 0.3.9
https://github.com/blacknon/hwatch/releases
(0.3.9 is a small bugfix, 0.3.8 is where the meat of this update is)
https://github.com/blacknon/hwatch/releases
(0.3.9 is a small bugfix, 0.3.8 is where the meat of this update is)