contrib/init/upstart: start on local-filesystems

This changes the upstart init script to start on `local-filesystems`.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Merge pull request #5840 from unclejack/upstart_mounted

Update contrib/init/upstart to "start on local-filesystems"