faa9a74c9e test: Fail wait_until early if connection is lost (MarcoFalke)
Pull request description:
Calling `minonode.wait_until` needs a connection to make progress (e.g. waiting for an inv), unless the mininode waits for the initial connection or for a disconnection. So for test development and failure debugging, fail early in all `wait_until`, unless opted out.
ACKs for top commit:
jnewbery:
Code review ACK faa9a74c9e.
Tree-SHA512: 4be850b96e23b87bc2ff42c028a5045d6f5cdbc9482ce6a6ba01cc5eb26710dab9e2ed547c363aac4bd5825151ee9996fb797261420b631bceeddbfa698d1dec