Document changes and release 2.5.7-3pureos2

debian/changelog

+geoclue-2.0 (2.5.7-3pureos2) byzantium; urgency=medium
+
+  * Fix 4G location.
+    In the 4G case we need to set the towerType to not fall back
+    to GeoIP location. All patches cherry-picked from upstream.
+
+ -- Guido Günther <agx@sigxcpu.org>  Fri, 23 Apr 2021 17:36:21 +0200
+
 geoclue-2.0 (2.5.7-3pureos1) unstable; urgency=medium
 
   * Move pureos patches into d/patches/pureos.