message: Fix wrong return type on SDObject
diff: @@ -420,7 +420,7 @@ struct SDObject
  inline double AsDouble() const { return data.basic.d; }
  inline float AsFloat() const { return (float)data.basic.d; }
  inline char AsChar() const { return data.basic.c; }
  - inline std::string AsString() const { return data.str; }
  + inline rdcstr AsString() const { return data.str; }
  inline uint64_t AsUInt64() const { return (uint64_t)data.basic.u; }
  inline int64_t AsInt64() const { return (int64_t)data.basic.i; }
  inline uint32_t AsUInt32() const { return (uint32_t)data.basic.u; }
  