Fix instructions for open street map routes.

In order to get instructions for an open street map route, 'instructions'
needs to be set to 'true' in the http request to
http://router.project-osrm.org/viaroute

Change-Id: Ia25ca806c8cd40f56bfa2a7aed0a2a519d63e074
Reviewed-by: Anders Gunnarsson <anders.gunnarsson@appello.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>