Fix unnecessary error log

Author: cyanfish

NAPS2.Lib.WinForms/EtoForms/Ui/WinFormsDesktopForm.cs

@@ -16,8 +16,6 @@ namespace NAPS2.EtoForms.Ui;
 
 public class WinFormsDesktopForm : DesktopForm
 {
-    public static WF.ApplicationContext? ApplicationContext { get; set; }
-
     private readonly Dictionary<DesktopToolbarMenuType, WF.ToolStripSplitButton> _menuButtons = new();
     private readonly ToolbarFormatter _toolbarFormatter = new(new StringWrapper());
     private readonly WF.Form _form;
@@ -109,17 +107,6 @@ protected override LayoutElement GetZoomButtons()
 
     private WF.ListView NativeListView => ((WinFormsListView<UiImage>) _listView).NativeControl;
 
-    protected override void SetMainForm(Form newMainForm)
-    {
-        base.SetMainForm(newMainForm);
-        if (ApplicationContext == null)
-        {
-            Log.Error("ApplicationContext should not be null");
-            return;
-        }
-        ApplicationContext.MainForm = newMainForm.ToSWF();
-    }
-
     protected override void SetCulture(string cultureId)
     {
         SaveToolStripLocation();

NAPS2.Lib/EtoForms/Ui/DesktopForm.cs

@@ -454,7 +454,7 @@ protected virtual void SetCulture(string cultureId)
             FormStateController.DoSaveFormState();
             var newDesktop = FormFactory.Create<DesktopForm>();
             newDesktop.Show();
-            SetMainForm(newDesktop);
+            Application.Instance.MainForm = newDesktop;
             Close();
         }
         finally
@@ -464,11 +464,6 @@ protected virtual void SetCulture(string cultureId)
         // TODO: If we make any other forms non-modal, we will need to refresh them too
     }
 
-    protected virtual void SetMainForm(Form newMainForm)
-    {
-        Application.Instance.MainForm = newMainForm;
-    }
-
     protected virtual void UpdateToolbar()
     {
         // Top-level toolbar items