PARIS — Rescuers resumed the difficult task of searching for the 150 victims of a deadly plane crash in the French Alps, as the search for clues was dealt a setback Wednesday afternoon. Investigators said they had so far been unable to retrieve any data from the plane’s cockpit voice recorder, and the inquiry has been hampered further, an official said, by the discovery that the second black box, which was found on Wednesday, was severely damaged, and its memory card dislodged and missing.