check backup date on symlink instead of dir

tests/test_backup.py

@@ -88,7 +88,6 @@ def test_last_backup_is_recent(server: str) -> bool:
             "-maxdepth 1",
             "-xtype l",
             "-name latest",
-            "-exec realpath {} +",  # must always be last arg
         )
         cmd = "ssh -o StrictHostKeyChecking=no {} '{}'".format(server, find)
         status, out = subprocess.getstatusoutput(cmd)