Remove unnecessary variable from CuraApplication

In response to feedback comment https://github.com/Ultimaker/Cura/pull/7904#discussion_r438022415

CURA-7454

cura/CuraApplication.py

@@ -1947,11 +1947,6 @@ class CuraApplication(QtApplication):
         # Only show the complete flow if there is no printer yet.
         return self._machine_manager.activeMachine is None
 
-    @pyqtSlot(result = bool)
-    def shouldShowAddPrintersUncancellableDialog(self) -> bool:
-        # If there is no printer and the user is logged in, show only the add printers flow in the welcome dialog.
-        return self._machine_manager.activeMachine is None and self.getCuraAPI().account.isLoggedIn
-
     @pyqtSlot(result = bool)
     def shouldShowWhatsNewDialog(self) -> bool:
         has_active_machine = self._machine_manager.activeMachine is not None

resources/qml/Cura.qml

@@ -135,7 +135,7 @@ UM.MainWindow
 
             // Reuse the welcome dialog item to show the "Add printers" dialog. Triggered when there is no active
             // machine and the user is logged in.
-            if (CuraApplication.shouldShowAddPrintersUncancellableDialog())
+            if (!Cura.MachineManager.activeMachine && Cura.API.account.isLoggedIn)
             {
                 welcomeDialogItem.model = CuraApplication.getAddPrinterPagesModelWithoutCancel()
                 welcomeDialogItem.progressBarVisible = false