CFSv2: [min/max]StartTime not applied to timestampsFiles

As reported by @joan.moragues : when calling CFSv2 with something like --injectSqrtSX=1 --IFOs H1 --timestampsFiles timestamps_H1.txt adding --minStartTime=1247845509 --maxStartTime 1258385272 (where the file covers a longer base duration) then it uses the full amount of data, ignoring the min/max.

The problem is in the ~20 lines starting at https://lscsoft.docs.ligo.org/lalsuite/lalapps/_compute_fstatistic__v2_8c_source.html#l01232 :

1. when one gives timestampsfiles, they are loaded as is and not cut to min/max
2. then the min/max get stored in constraints
3. and in the next if/else, those constraints are only used on reading real data files, not on the "fake catalog" generated from timestamps

Shouldn't be too difficult to fix, but unlikely this year.