DAL/Node: remove trap warning for a delegate that did not TB attest

A warning is emitted when the node finds a trap for an attester who did not TB attest. There is no reason to emit a warning in such a case.

The warning was introduced to deal with the special case where there was an attestation operation included but the delegate could not be retrieved from the operation's receipt. However, this special case was not correctly identified. See this comment from !16281 (merged) for more context.