Fix centerdoc for latest master changes

Author: jgmdev

manifest.json

@@ -257,7 +257,7 @@
       "id": "centerdoc",
       "mod_version": "3",
       "path": "plugins/centerdoc.lua",
-      "version": "0.2.5"
+      "version": "0.2.6"
     },
     {
       "description": "Hides the treeview at start if no arguments passed to the executable are directories. Compatible with lite.",

plugins/centerdoc.lua

@@ -63,7 +63,9 @@ local previous_tabs_status
 local previous_line_numbers_status
 
 local function save_previous_status()
-  previous_win_status = system.get_window_mode(core.window)
+  previous_win_status = core.window
+    and system.get_window_mode(core.window)
+    or core.window_mode
   previous_treeview_status = treeview.visible
   previous_statusbar_status = core.status_view.visible
   previous_tabs_status = config.hide_tabs