Problem: expired ibc channel recovery not tested

[tomtau]

I guess the test will be something like this:

• two chains with short unbonding time / trusting period
• establish ibc channel, but shutdown a relayer to let the channel expire
• startup the relayer again, create a new ibc channel, and submit and approve the proposal to recover the expired channel:

chain-maind tx gov  submit-proposal update-client -h
Submit an update IBC client proposal along with an initial deposit.
Please specify a subject client identifier you want to update..
Please specify the substitute client the subject client will be updated to.

Usage:
  chain-maind tx gov submit-proposal update-client [subject-client-id] [substitute-client-id] [flags]

• check stuff works over the substitute client