debian/changelog: UNRELEASED => unstable

Gbp-Dch: Ignore

debian/changelog

-openexr (2.3.0-6) UNRELEASED; urgency=medium
+openexr (2.3.0-6) unstable; urgency=medium
 
   * Upload to unstable (Closes: #919036)
   * debian/: debhelper bump 11 -> 12
   * debian/control: S-V bump 4.3.0 -> 4.4.0 (no changes needed)
 
- -- Matteo F. Vescovi <mfv@debian.org>  Mon, 02 Sep 2019 16:18:43 +0200
+ -- Matteo F. Vescovi <mfv@debian.org>  Mon, 02 Sep 2019 16:23:00 +0200
 
 openexr (2.3.0-5) experimental; urgency=medium