Document changes and release 1:78.7.0-1~deb10u1

debian/changelog

+thunderbird (1:78.7.0-1~deb10u1) stable-security; urgency=medium
+
+  * Rebuild for buster-security
+
+ -- Carsten Schoenert <c.schoenert@t-online.de>  Sat, 30 Jan 2021 11:37:31 +0100
+
 thunderbird (1:78.7.0-1) unstable; urgency=medium
 
   * [8751354] New upstream version 78.7.0