Update d/ch for 2.664.43 release

debian/changelog

@@ -1,7 +1,7 @@
-livecd-rootfs (2.664.42) UNRELEASED; urgency=medium
+livecd-rootfs (2.664.43) focal; urgency=medium
 
-  * ubuntu-cpc: Install `shim-signed` and `grub-efi-arm64-signed` to enable
+  * ubuntu-cpc: Install `shim-signed` and `grub-efi-arm64-signed` to
-    secureboot on ARM64 images (LP:#1980358)
+    enable secureboot on ARM64 images (LP: #1980358)
 
  -- Ivan Kapelyukhin <ivan.kapelyukhin@canonical.com>  Thu, 30 Jun 2022 14:06:30 +0200