Fixed configuration block rendering in routing docs

Author: mickaelandrieu

routing.rst

@@ -22,7 +22,7 @@ Creating Routes
 
 A *route* is a map from a URL path to a controller. Suppose you want one route that
 matches ``/blog`` exactly and another more dynamic route that can match *any* URL
-like ``/blog/my-post`` or ``/blog/all-about-symfony``::
+like ``/blog/my-post`` or ``/blog/all-about-symfony``:
 
 .. configuration-block::