SW-557: new offset computation by sander

RTCP/Cobalt/OutputProc/src/TBB_Dipole.cc

@@ -300,7 +300,7 @@ namespace LOFAR
         }
         offset += (frame.header.time - time0) / 2; // 1 extra slice every 2 seconds
       }
-      offset += sliceNr - itsDumpInfo.itsSampleNrOrSliceNr0;
+      offset += (sliceNr - itsDumpInfo.itsSampleNrOrSliceNr0) / SPECTRAL_TRANSFORM_SIZE;
 
       /*
        * Flag lost frame(s) (assumes no out-of-order).