message: Avoid -Wshadow errors
  Suggested by Pavel Janik.
  backports bitcoin@a603925c77d7cd15c03d8028414c8917347e81b7
diff: @@ -489,7 +489,7 @@ protected:
  std::string& string;
  public:
  - LimitedString(std::string& string) : string(string) {}
  + LimitedString(std::string& _string) : string(_string) {}
  template <typename Stream>
  void Unserialize(Stream& s)
  @@ -855,9 +855,9 @@ protected:
  public:
  CSizeComputer(int nTypeIn, int nVersionIn) : nSize(0), nType(nTypeIn), nVersion(nVersionIn) {}
  - void write(const char* psz, size_t nSize)
  + void write(const char* psz, size_t _nSize)
  {
  - this->nSize += nSize;
  + this->nSize += _nSize;
  }
  /** Pretend _nSize bytes are written, without specifying them. */
  