[kupfer] keybindings: Allow unbinding with bind_key(None)

[Ulrik Sverdrup <usverdrup src gnome org>]

commit 4b72882aa504e5518ad4f5af70a5a92fe4c7b8ae
Author: Ulrik Sverdrup <ulrik sverdrup gmail com>
Date:   Sat Aug 22 21:34:23 2009 +0200

    keybindings: Allow unbinding with bind_key(None)

 kupfer/keybindings.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/kupfer/keybindings.py b/kupfer/keybindings.py
index cb22d9b..0862356 100644
--- a/kupfer/keybindings.py
+++ b/kupfer/keybindings.py
@@ -52,7 +52,7 @@ def bind_key(keystr, keybinding_target=KEYBINDING_DEFAULT):
 
 	keybinding_target = int(keybinding_target)
 	callback = lambda : GetKeyboundObject()._keybinding(keybinding_target)
-	if len(keystr) == 1:
+	if keystr and len(keystr) == 1:
 		pretty.print_error(__name__, "Refusing to bind key", repr(keystr))
 		return False