Retrying to initiate a transfer plus receiving an invalid secret request for it seems to confuse the client

[jomuel]

Calling raiden.transfer.node.state_transition with the following sequence of actions results in a failing assertion ("lock is already registered"):

• ActionInitInitiator
• an invalid ReceiveSecretRequest for the initiated transfer, e. g. one in which the amount is wrong
• the same ActionInitInitiator again

This is the first issue we found by fuzz testing, so we are not certain it is an actual bug. To reproduce, run test_failing_path_2 in the wip pull request #2887.

[hackaugusto]

This is the same problem as #3001 , but instead of receiving a new secret request the transfer is "restarted". So, I'm going to close this as a duplicate.