Use same gist path as setup_test_data

`dgit-cluster-backup-routes` needs to use the same fake gist route as
`test/testlib.sh`.  Now it does.

Author: Patrick Reynolds

test/bin/dgit-cluster-backup-routes

@@ -22,7 +22,7 @@ if [[ "$GHE_REMOTE_VERSION" =~ 2.16. && "$(version $GHE_REMOTE_VERSION)" -ge "$(
     echo 0/nw/01/aa/3f/1234 git-server-fake-uuid
     echo 1/nw/23/bb/4c/2345 git-server-fake-uuid1
     echo 0/01/aa/3f/gist/93069ad4c391b6203f183e147d52a97a.git git-server-fake-uuid2
-    echo 1/23/bb/4c/gist/03de86b717f901789a864375baaab36c.git git-server-fake-uuid
+    echo 1/23/bb/4c/gist/1234.git git-server-fake-uuid
 else
     echo 0/nw/01/aa/3f/1234 git-server-fake-uuid
     echo 1/nw/23/bb/4c/2345 git-server-fake-uuid1