Document changes and release 1:91.2.1-1

debian/changelog

+thunderbird (1:91.2.1-1) unstable; urgency=medium
+
+  [ Carsten Schoenert ]
+  * [bcb5677] d/gbp.conf: Adjust to upstream-91.x
+  * [12a433a] New upstream version 91.2.1
+  * [f935b52] Rebuild patch queue from patch-queue branch
+    Added patch:
+    debian-hacks/Fix-Floating-Point-Normalization-breakage-on-32bit-Linux.patch
+  * [3faba71] Disable usage of system icu package
+    The system packages of libicu-dev are to old for Thunderbird, we need to
+    use the internel pre-shipped ICU sources.
+
+ -- Carsten Schoenert <c.schoenert@t-online.de>  Sat, 23 Oct 2021 08:59:32 +0200
+
 thunderbird (1:91.2.0-1) experimental; urgency=medium
 
   * [3c88844] New upstream version 91.2.0