Fix reference to addAdditionalComponents and updateAdditionalComponents

Nobody ever tested this, I think...

Contributes to issue CURA-4741.

resources/qml/MonitorButton.qml

@@ -199,12 +199,12 @@ Item
         }
 
         Component.onCompleted: {
-            updateAdditionalComponents("monitorButtons")
+            buttonsRow.updateAdditionalComponents("monitorButtons")
         }
 
         Connections {
             target: CuraApplication
-            onAdditionalComponentsChanged: updateAdditionalComponents
+            onAdditionalComponentsChanged: buttonsRow.updateAdditionalComponents
         }
 
         function updateAdditionalComponents (areaId) {

resources/qml/SaveButton.qml

@@ -138,12 +138,12 @@ Item {
         }
 
         Component.onCompleted: {
-            addAdditionalComponents("saveButton")
+            saveRow.addAdditionalComponents("saveButton")
         }
 
         Connections {
             target: CuraApplication
-            onAdditionalComponentsChanged: addAdditionalComponents
+            onAdditionalComponentsChanged: saveRow.addAdditionalComponents("saveButton")
         }
 
         function addAdditionalComponents (areaId) {