c&p improvement for 13.04

first line killed sources list

docs/sources/installation/ubuntulinux.rst

@@ -133,7 +133,8 @@ to follow them again.*
    sudo sh -c "wget -qO- https://get.docker.io/gpg | apt-key add -"
 
    # Add the Docker repository to your apt sources list.
-   sudo sh -c "echo deb http://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list"
+   sudo sh -c "echo deb http://get.docker.io/ubuntu docker main\
+   > /etc/apt/sources.list.d/docker.list"
 
    # update
    sudo apt-get update