rpm-ostree: user older tzdata package (#468)

rpm-ostree version on RHEL Atomic Host is too old to support the ztsd
compression used in the newer Fedora tzdata packages causing the test to
fail with "Unrecognized archive format".

Author: mike-nguyen

tests/rpm-ostree/vars.yml

@@ -3,4 +3,4 @@
 g_pkg: 'wget'
 g_remove_pkg: 'bash-completion'
 g_replace_pkg: 'tzdata'
-g_replace_pkg_url: 'https://download.fedoraproject.org/pub/fedora/linux/releases/32/Everything/x86_64/os/Packages/t/tzdata-2019c-3.fc32.noarch.rpm'
+g_replace_pkg_url: 'https://kojipkgs.fedoraproject.org//vol/fedora_koji_archive04/packages/tzdata/2020a/1.fc30/noarch/tzdata-2020a-1.fc30.noarch.rpm'