Update changelog for 0.80+dfsg-1 release

debian/changelog

+astrometry.net (0.80+dfsg-1) unstable; urgency=medium
+
+  * New upstream version 0.80+dfsg. Rediff patches
+  * Remove removal of ngc2000 from d/copyright: replaced by openngc
+  * Push Standards-Version to 4.5.0. No changes needed.
+
+ -- Ole Streicher <olebole@debian.org>  Tue, 28 Apr 2020 09:13:39 +0200
+
 astrometry.net (0.78+dfsg-3) unstable; urgency=low
 
   * Adjust new source-extractor name (Closes: #944802)