Release apertis-update-manager version 0.2020.31

Signed-off-by: Emanuele Aina <emanuele.aina@collabora.com>

debian/changelog

+apertis-update-manager (0.2020.31) apertis; urgency=medium
+
+  * managerd: Harmonize the default bootlimit to 3
+
+ -- Emanuele Aina <emanuele.aina@collabora.com>  Tue, 04 Jan 2022 16:00:05 +0000
+
 apertis-update-manager (0.2020.30) apertis; urgency=medium
 
   [ Gireesh Hiremath ]