Update changelog in spec file

Author: matyasselmeci

rpm/vmu-packer.spec

@@ -34,6 +34,7 @@ echo '{"password":"ENTER PASSWORD HERE"}' > %{buildroot}/etc/%{name}/password.js
 * Wed Jun 23 2021 Mátyás Selmeci <matyas@cs.wisc.edu> - 1.2.0-1
 - Name the CentOS Stream 8 image centos_stream_8 instead of centos_8_stream
 - Add Rocky Linux 8.4
+- Use default file system type in CentOS 8 images instead of forcing ext4
 
 * Tue Jan 12 2021 Mátyás Selmeci <matyas@cs.wisc.edu> - 1.1.1-1
 - Build CentOS 8 Stream in vmu-rebuild-all