Fix fluctuations in distant beams

I think I found a bug in the calculation of the distant fluctuations in both carrier and sideband beams. As I read it, at the moment, the GW signal and TTl couples to the local offsets. Shouldn't they couple to the propagated distant ones as indicated also in the "Unified model document" (see \nu_{21}^o below)?

In my opinion

self.distant_carrier_fluctuations = \
    propagated_carrier_fluctuations \
    - (self.central_freq + self.local_carrier_offsets) * self.gws \
    - (self.central_freq + self.local_carrier_offsets) * self.local_ttls / c

should really read

self.distant_carrier_fluctuations = \
    propagated_carrier_fluctuations \
    - (self.central_freq + self.distant_carrier_offsets) * self.gws \
    - (self.central_freq + self.distant_carrier_offsets) * self.local_ttls / c

or am I missing something?