documentation: broken link to std.bind

[Bastiaan Veelo]

In the side-bar for phobos 
http://www.digitalmars.com/d/phobos/phobos.html the link to std.bind 
says http://www.digitalmars.com/d/phobos/std_bind instead of 
http://www.digitalmars.com/d/phobos/std_bind.html.

Best regards,
Bastiaan.