iter_bliss_scan_data_from_memory yields many lima arrays if counter_names is empty

Tested with bliss-demo-session: loopscan(count_time=0.1, npoints=5) if the counter_names is an empty list, it iterates more times than points in the scan

for ind, x in enumerate(self.iter_bliss_data_from_memory(
    db_name=scan_key,
    lima_names=["beamviewer"],
    counter_names=[],
)):
    pass
print(ind)

9

if we add a counter (diode1 for example), it iterates the correct number of points

for ind, x in enumerate(self.iter_bliss_data_from_memory(
    db_name=scan_key,
    lima_names=["beamviewer"],
    counter_names=["diode1"],
)):
    pass
print(ind)

4