API server crash after running Rebalance.py plugin

[saubyk]

Below tickets cover the issue details:
lightningd/plugins#134
Ride-The-Lightning/RTL#439

[saubyk]

@BTCBellyButton
Trying to replicate this issue locally. Can you please link the rebalancing library that you are running with C-Lightning-REST? I couldn't find it on my own.

[BTCBellyButton]

Sure.
Here it is: https://github.com/lightningd/plugins/tree/master/rebalance