[verisure] Fix switch fall-through in event log getValue

Address Copilot review comment on #20353.

CHANNEL_LAST_EVENT_TIME fell through into CHANNEL_LAST_EVENT_DEVICE_TYPE,
which returned the device type label. As a result, getValue(CHANNEL_LAST_EVENT_TIME, ...)
could update the timestamp channel with the wrong state when eventTime was
null and updateTimeStamp(...) was skipped.

Add an explicit return for CHANNEL_LAST_EVENT_TIME so the side-effect call
to triggerEventChannels still runs but no incorrect state is returned. The
actual timestamp value is set by the subsequent updateTimeStamp call in
updateEventLogState when eventTime is non-null.

Signed-off-by: Jan Gustafsson <jannegpriv@gmail.com>

Author: jannegpriv

bundles/org.openhab.binding.verisure/src/main/java/org/openhab/binding/verisure/internal/handler/VerisureEventLogThingHandler.java

@@ -128,6 +128,7 @@ public State getValue(String channelId, VerisureEventLogDTO verisureEventLog, Ev
                 if (lastEventTime != 0) {
                     triggerEventChannels(eventLog);
                 }
+                return UnDefType.UNDEF;
             case CHANNEL_LAST_EVENT_DEVICE_TYPE:
                 Gui gui = device != null ? device.getGui() : null;
                 String label = gui != null ? gui.getLabel() : null;