This can happen when a non-waited-for answers is followed by a waited-for
answer for the same node: the first answer is for the same connection, but
has a different msg_id, so it was just dropped.

git-svn-id: https://svn.erp5.org/repos/neo/trunk@2495 71dcc9de-d417-0410-9af5-da40c76e7ee4