Updated debian changelog for version 0.7.3

debian/changelog

+swh-model (0.7.3-1~swh1) unstable-swh; urgency=medium
+
+  * New upstream release 0.7.3     - (tagged by Nicolas Dandrimont
+    <nicolas@dandrimont.eu> on 2020-10-27 16:03:58 +0100)
+  * Upstream changes:     - Release swh.model v0.7.3     - Reduce the
+    amount of DeprecationWarnings for RawExtrinsicMetadata
+
+ -- Software Heritage autobuilder (on jenkins-debian1) <jenkins@jenkins-debian1.internal.softwareheritage.org>  Tue, 27 Oct 2020 15:06:50 +0000
+
 swh-model (0.7.2-1~swh1) unstable-swh; urgency=medium
 
   * New upstream release 0.7.2     - (tagged by Nicolas Dandrimont