update indigo

Reviewer: trivial

* submodules/indigo 8356f8b...37022d3 (2):
 > Merge into master from pull request #56: Indigo code cleanup
(https://github.com/floodlight/indigo/pull/56)
 > Merge into master from pull request #58: Make OFConnection manger OF
version compile time configurable.
(https://github.com/floodlight/indigo/pull/58)

Calls to indigo_cxn_send_controller_message needed to be changed.