openstack-debian-7.0-user-data.txt: fix symlink

The file this symlink was pointing to no longer exists.

Signed-off-by: Nathan Cutler <ncutler@suse.com>

diff --git a/teuthology/openstack/openstack-debian-7.0-user-data.txt b/teuthology/openstack/openstack-debian-7.0-user-data.txt
index a51b0cc9bcda9768b680a3533cb5efc355be46d4..1c0d25675966f313d167eca84072c07b54740d5d 120000 (symlink)
--- a/teuthology/openstack/openstack-debian-7.0-user-data.txt
+++ b/teuthology/openstack/openstack-debian-7.0-user-data.txt
@@ -1 +1 @@
-openstack-ubuntu-user-data.txt
\ No newline at end of file
+openstack-ubuntu-14.04-user-data.txt
\ No newline at end of file