This addresses and issue when gpsdate is running and the gpsd will be
killed (testing coredump handling).
The issue is within the libgps cod itself that doesn't handle the
result(0) of the recv syscall correctly and keeps on looping. Now in a
normal system gpsdate should only execute at the beginning and exit once
there is a date. So the window for this runtime failure is quite low.
Bug reported by Holger Freyther.