test: Update message for netplan apply dbus issue

5d587ec used an error that has changed between versions.

tests/integration_tests/util.py

@@ -210,7 +210,9 @@ def verify_clean_log(log: str, ignore_deprecations: bool = True):
     if "found network data from DataSourceNone" in log:
         warning_texts.append("Used fallback datasource")
     if "['netplan', 'apply']" in log:
-        warning_texts.append("Failed to connect system bus")
+        warning_texts.append(
+            "Falling back to a hard restart of systemd-networkd.service"
+        )
     if "oracle" in log:
         # LP: #1842752
         lease_exists_text = "Stderr: RTNETLINK answers: File exists"