LP1271559 fix z39.50 timeout Staff Client network error

LP1271559  fix z39.50 timeout Staff Client network error

When doing a z39.50 search in the staff client, if a z39.50 server
timesout, then the result set returned is null.  Currenlty, this breaks
the code on the server and sends a Network Error to the staff client.

This code adds a check to ensure that the results are populated in order
to avoid creating the server error.