v0 calibration files have moved

Recently, the naming convention for v0 calibration envelopes has changed from, e.g.,

/home/cal/public_html/archive/H1/uncertainty/v0/1406/561064/calibration_uncertainty_H1_1406561064.txt

to

/home/cal/public_html/archive/H1/uncertainty/v0/1406/564662/calibration_uncertainty_H1_1406564662_pydarm.txt

These new files are not to be used.

We need to update calibration_lookup_o4 to ignore directories that don't contain an uncertainty envelope.