org.texi: fix typo about defining an org-capture key.

doc/org.texi

@@ -6291,8 +6291,8 @@ through the interactive template selection, you can create your key binding
 like this:
 
 @lisp
-(define-key global-map "\C-c c"
-   (lambda () (interactive) (org-capture "t")))
+(define-key global-map "\C-cc"
+   (lambda () (interactive) (org-capture nil "t")))
 @end lisp
 
 @menu