releasing package dulwich version 0.18.3-2

debian/changelog

@@ -1,6 +1,6 @@
-dulwich (0.18.3-2) UNRELEASED; urgency=medium
+dulwich (0.18.3-2) unstable; urgency=medium
 
-  * Fix argument order to dh_install.
+  * Fix dh_install invocation.
 
  -- Jelmer Vernooij <jelmer@debian.org>  Thu, 28 Sep 2017 00:47:21 +0100