New upstream release.

debian/changelog

@@ -1,8 +1,12 @@
-dulwich (0.19.1-2) UNRELEASED; urgency=medium
+dulwich (0.19.3-1) UNRELEASED; urgency=medium
 
+  [ Ondřej Nový ]
   * d/control: Remove ancient X-Python-Version field
   * d/control: Remove ancient X-Python3-Version field
 
+  [ Jelmer Vernooij ]
+  * New upstream release.
+
  -- Ondřej Nový <onovy@debian.org>  Mon, 14 May 2018 08:04:38 +0200
 
 dulwich (0.19.1-1) unstable; urgency=medium