qa/suites/rados/thrash-old-clients: use centos_latest.yaml

use centos_latest instead of bionic because this is only common
distro for which we build packages for nautilus and above.

Signed-off-by: Neha Ojha <nojha@redhat.com>

diff --git a/qa/suites/rados/thrash-old-clients/distro$/centos_latest.yaml b/qa/suites/rados/thrash-old-clients/distro$/centos_latest.yaml
new file mode 120000 (symlink)
index 0000000..bd9854e
--- /dev/null
+++ b/qa/suites/rados/thrash-old-clients/distro$/centos_latest.yaml
@@ -0,0 +1 @@
+.qa/distros/supported/centos_latest.yaml
\ No newline at end of file

diff --git a/qa/suites/rados/thrash-old-clients/distro$/ubuntu_18.04.yaml b/qa/suites/rados/thrash-old-clients/distro$/ubuntu_18.04.yaml
deleted file mode 120000 (symlink)
index cfb85f1..0000000
--- a/qa/suites/rados/thrash-old-clients/distro$/ubuntu_18.04.yaml
+++ /dev/null
@@ -1 +0,0 @@
-.qa/distros/all/ubuntu_18.04.yaml
\ No newline at end of file