Migrated deprecated funtion gtk_image_menu_item_new_from_stock to gtk_menu_item_new_with_mnemonic

src/mssh-window.c

@@ -475,15 +475,13 @@ static void mssh_window_init(MSSHWindow* window)
     GtkWidget *server_item = gtk_menu_item_new_with_label("Servers");
     GtkWidget *command_item = gtk_menu_item_new_with_label("Commands");
 
-    GtkWidget *file_quit = gtk_image_menu_item_new_from_stock(
-        GTK_STOCK_QUIT, NULL);
+    GtkWidget *file_quit = gtk_menu_item_new_with_mnemonic("_Quit");
     GtkWidget *file_sendhost = gtk_image_menu_item_new_with_label(
         "Send hostname");
     GtkWidget *file_add = gtk_menu_item_new_with_label(
         "Add session");
 
-    GtkWidget *edit_pref = gtk_image_menu_item_new_from_stock(
-        GTK_STOCK_PREFERENCES, NULL);
+    GtkWidget *edit_pref = gtk_menu_item_new_with_mnemonic("_Preferences");
 
     GtkAccelGroup *accel = gtk_accel_group_new();