CURA-4485 Activate configuration option disabled in printers within a

cluster.
Just allow when there is a cluster with just one printer.

plugins/UM3NetworkPrinting/NetworkClusterPrinterOutputDevice.py

@@ -220,7 +220,9 @@ class NetworkClusterPrinterOutputDevice(NetworkPrinterOutputDevice.NetworkPrinte
         self.setPrinters(json_data)
 
     def materialHotendChangedMessage(self, callback):
-        pass # Do nothing.
+        # When there is just one printer, the activate configuration option is enabled
+        if (self._cluster_size == 1):
+            super().materialHotendChangedMessage(callback = callback)
 
     def _startCameraStream(self):
         ## Request new image

plugins/UM3NetworkPrinting/UM3InfoComponents.qml

@@ -115,8 +115,16 @@ Item
         {
             tooltip: catalog.i18nc("@info:tooltip", "Load the configuration of the printer into Cura")
             text: catalog.i18nc("@action:button", "Activate Configuration")
-            visible: printerConnected
+            visible: printerConnected && !isClusterPrinter()
             onClicked: manager.loadConfigurationFromPrinter()
+
+            function isClusterPrinter() {
+                var clusterSize = Cura.MachineManager.printerOutputDevices[0].clusterSize
+                // This is a non cluster printer or the cluster it is just one printer
+                if (typeof clusterSize == "undefined" || clusterSize == 1)
+                    return false
+                return true
+            }
         }
     }