Refs #10: remove gvwstate.dat file if pc.recovery=0 to avoid read stale state file.
This situation could happens in following scenario.
1. node starts up with pc.recovery=1, and has state file
2. then node starts up with pc.recovery=0, so right now state file is stale.
3. then node starts up with pc.recovery=1 again, stale file is used.