- add a stop in ADEXCH_UV_AGRID_3D_RX if trying to use it with EXCH2:   was calling a forward exch2, which is wrong ; used in SEAICE & EXF pkgs.
- add a stop in ADEXCH_UV_AGRID_3D_RX if trying to use it with EXCH2:
  was calling a forward exch2, which is wrong ; used in SEAICE & EXF pkgs.

altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h