Resolve "Ubuntu 20 not compiling"

include/core/state_block/state_composite.h

@@ -99,7 +99,7 @@ class MatrixComposite : public std::unordered_map < char, std::unordered_map < c
                         const std::list<int>& _row_sizes,
                         const StateStructure& _col_structure,
                         const std::list<int>& _col_sizes);
-        MatrixComposite (const MatrixComposite& m);
+
         /**
          * \brief Construct from Eigen::VectorXd and structure
          *
@@ -358,11 +358,6 @@ inline StateBlockPtr wolf::StateBlockComposite::emplace(const char &_sb_type,
     return sb;
 }
 
-inline MatrixComposite::MatrixComposite (const MatrixComposite& m)
-        : unordered_map<char, unordered_map<char, MatrixXd> >(m), size_rows_(m.size_rows_), size_cols_(m.size_cols_)
-{
-}
-
 }