Set total data loaded for the PSD calculation from frame file to be `psd_duration`
There was a typo in the way the strain data was set for the PSD calculation when reading from a frame file. In line 654 of detector.py
, t2 was set such that the total duration of the loaded data was psd_offset
instead of psd_duration
. I've just changed the definition of t2 so that the total data loaded is psd_duration
.