Fix example in std::Option

Author: Grigoriy

src/libstd/option.rs

@@ -28,7 +28,7 @@ let msg = Some(~"howdy");
 
 // Take a reference to the contained string
 match msg {
-    Some(ref m) => io::println(m),
+    Some(ref m) => io::println(*m),
     None => ()
 }