[irobot] Fix failing test (fix thing UID) (#12623)

Fix #12621

Signed-off-by: Laurent Garnier <lg.hc@free.fr>

bundles/org.openhab.binding.irobot/src/test/java/org/openhab/binding/irobot/internal/handler/RoombaHandlerTest.java

@@ -60,7 +60,7 @@ public class RoombaHandlerTest {
     @Nullable
     private RoombaHandler handler;
     // We have to initialize it to avoid compile errors
-    private @Mock Thing thing = new ThingImpl(new ThingTypeUID("AA:BB"), "");
+    private @Mock Thing thing = new ThingImpl(new ThingTypeUID("AA:BB"), "test");
     @Nullable
     private ThingHandlerCallback callback;