update indigo

* 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.
Merge into master from pull request #72:
update indigo (https://github.com/floodlight/ivs/pull/72)