update changelog

debian/changelog

+hdf5-external-filter-plugins-static (1.10.6-6+deb11u1~fsec) bullseye; urgency=medium
+
+  [ jkotan ]
+  * change installation directory to serial/plugins
+
+ -- Jan Kotanski (jkotan) <jankotan@gmail.com>  Tue, 22 Jun 2021 15:03:49 +0200
+
 hdf5-external-filter-plugins-static (1.10.6-5+deb11u1~fsec) bullseye; urgency=medium
 
   [ Jan Kotanski ]