Prevent endless skeleton loading on Cloud

Contributes to CL-1154

For you @christerbeke

plugins/UM3NetworkPrinting/resources/qml/MonitorQueue.qml

@@ -160,7 +160,17 @@ Item
                 }
                 printJob: modelData
             }
-            model: OutputDevice.receivedPrintJobs ? OutputDevice.queuedPrintJobs : [null,null]
+            model:
+            {
+                // When printing over the cloud we don't recieve print jobs until there is one, so
+                // unless there's at least one print job we'll be stuck with skeleton loading
+                // indefinitely.
+                if (Cura.MachineManager.activeMachineHasActiveCloudConnection)
+                {
+                    return OutputDevice.queuedPrintJobs
+                }
+                return OutputDevice.receivedPrintJobs ? OutputDevice.queuedPrintJobs : [null,null]
+            }
             spacing: 6  // TODO: Theme!
         }
     }