H1:PSL-FSS_MIXER_OFS set to zero.

H1:PSL-FSS_MIXER_OFS, which is a mixer offset adjust. was set to -1.634V. That seems high. I couldn't find any alog about setting it. And the ODC bit was set at 0.8V and was alarming. After discussing it with Rick, I set it to zero and verified that the FSS is still locking fine. We should verify (by blocking the light on the diode) that zero is a reasonable setting.