Remove non const function

include/core/state_block/has_state_blocks.h

@@ -23,7 +23,6 @@ class HasStateBlocks
         virtual ~HasStateBlocks();
 
         const std::string& getStructure() const {return structure_;}
-        std::string& getStructure() {return structure_;}
         void appendToStructure(const std::string& _frame_type){structure_ += _frame_type;}
         const std::map<std::string, StateBlockPtr>& getStateBlockMap() const;
         std::map<std::string, StateBlockPtr>& getStateBlockMap();