Fix not displaying configuration with both extruders empty

cura/PrinterOutput/Models/PrinterConfigurationModel.py

@@ -58,6 +58,14 @@ class PrinterConfigurationModel(QObject):
                 return False
         return self._printer_type != ""
 
+    def hasAnyMaterialLoaded(self) -> bool:
+        if not self.isValid():
+            return False
+        for configuration in self._extruder_configurations:
+            if configuration.activeMaterial and configuration.activeMaterial.type != "empty":
+                return True
+        return False
+
     def __str__(self):
         message_chunks = []
         message_chunks.append("Printer type: " + self._printer_type)

cura/PrinterOutput/PrinterOutputDevice.py

@@ -222,7 +222,7 @@ class PrinterOutputDevice(QObject, OutputDevice):
     def _updateUniqueConfigurations(self) -> None:
         all_configurations = set()
         for printer in self._printers:
-            if printer.printerConfiguration is not None:
+            if printer.printerConfiguration is not None and printer.printerConfiguration.hasAnyMaterialLoaded():
                 all_configurations.add(printer.printerConfiguration)
             all_configurations.update(printer.availableConfigurations)
         new_configurations = sorted(all_configurations, key = lambda config: config.printerType)