message: fix compilation error when using 64bit index type
diff: @@ -18,7 +18,7 @@ namespace multimat
  template <typename Field2DType>
  class MMSubField2D
  - : public slam::SubMap<typename Field2DType::BiVarMapType, slam::RangeSet<int, int>>
  + : public slam::SubMap<typename Field2DType::BiVarMapType, slam::RangeSet<> >
  {
  public:
  using SubSetType = MultiMat::RangeSetType;
  