Add tzdata to buildd images

It isn't strictly build-essential, but it has traditionally been present
in both Debian and Ubuntu, and a variety of things fail without it.

debian/changelog

@@ -1,3 +1,11 @@
+livecd-rootfs (2.596) UNRELEASED; urgency=medium
+
+  * Add tzdata to buildd images.  It isn't strictly build-essential, but it
+    has traditionally been present in both Debian and Ubuntu, and a variety
+    of things fail without it.
+
+ -- Colin Watson <cjwatson@ubuntu.com>  Wed, 19 Jun 2019 17:20:16 +0100
+
 livecd-rootfs (2.595) eoan; urgency=medium
 
   * Remove dangling symlink

live-build/auto/config

@@ -813,6 +813,9 @@ case $SUBPROJECT in
 		add_package install build-essential
 		# Needed for LXD-based builds.
 		add_package install init
+		# Not strictly build-essential, but traditionally present
+		# and a variety of things fail without it.
+		add_package install tzdata
 
 		cp -af /usr/share/livecd-rootfs/live-build/make-lxd-metadata.py config/make-lxd-metadata
 		;;