Fix cyclic_glue system test

The cyclic_glue system test was waiting for `running` log after
an `rndc reload` command, but wasn't waiting for the log saying a
specific zone which changed has been reloaded `zone <zone>/IN: loaded`.

As a result, the test could randomly fails. This is now fixed.

bin/tests/system/cyclic_glue/tests_cyclic_glue.py

@@ -50,7 +50,7 @@ def test_cyclic_glues(ns1, ns4, templates):
     templates.render("ns1/root.db", {"broken_ns": True})
     with ns1.watch_log_from_here() as watcher:
         ns1.rndc("reload")
-        watcher.wait_for_line("running")
+        watcher.wait_for_line(["running", "zone ./IN: loaded serial"])
 
     with ns4.watch_log_from_here() as watcher:
         ns4.rndc("flush")