Coordinator should not deliver dispatcher configuration

[juagargi]

At the moment, many control services are configured outside the dispatched-ports range (ports where the border router sends directly, without needing a dispatcher; configured in topology.json), and thus the dispatcher receives packets intended for the CS, and forwards them to it.
For that, the dispatcher needs configuration specifying where the CS is, e.g.

[dispatcher.service_addresses]
"17-ffaa:1:c40,CS" = "127.0.0.1:30254"
"17-ffaa:1:c40,DS" = "127.0.0.1:30254"

If we modify the configuration of the CS in our scionlab infrastructure and user ASes to make all the CSs listen inside the range of the dispatched-ports, or widen the range to include the existing CSs in scionlab, we don't need that configuration.

• Modify either the configuration of all CSs in scionlab or the dispached-ports value written in topology.json, so that all CSs are inside the range.
• Remove the ability of the coordinator to generate dynamically the dispatcher.toml file.
• Make the end-host running scionlab-config script remove the dispatcher.toml file it wrote last time when it got it from the Coordinator. Otherwise dpkg will refuse to install a new one when a new package is installed.