Fix typo in desktop id

Author: j4321

tkfilebrowser/filebrowser.py

@@ -302,7 +302,7 @@ def __init__(self, parent, initialdir="", initialfile="", mode="openfile",
 
         # -------- desktop
         try:
-            desktop = check_output(['xdg-users-dir', 'DESKTOP']).decode().strip()
+            desktop = check_output(['xdg-user-dir', 'DESKTOP']).decode().strip()
         except Exception:
             # FileNotFoundError in python3 if xdg-users-dir is not installed,
             # but OSError in python2