ENG-5050

 Eliminate a harmless but scary log message with belt, suspenders, and staples:
- Check for trace-level logging enabled before calling that log method
  on log4j
- Construct an actual empty parameter set to feed the empty
  FragmentTaskMessage that we use to serialize multiple restart attempts
  when the first batch is a local read fragment.
- When printing the message to the console, print a special message
  describing the message purpose rather than empty FragmentData.