message: [Wallet] Remove (explicitely) unused tx comparator
  We remove the '==' and '!=' operators from CMutableTransaction.
  These comparators are never explicitely used in our code.
  As it turns out, it was used implicitely and created this situation:
  So this change fixes
diff: @@ -325,17 +325,6 @@ struct CMutableTransaction
  uint256 GetHash() const;
  std::string ToString() const;
  -
  - friend bool operator==(const CMutableTransaction& a, const CMutableTransaction& b)
  - {
  - return a.GetHash() == b.GetHash();
  - }
  -
  - friend bool operator!=(const CMutableTransaction& a, const CMutableTransaction& b)
  - {
  - return !(a == b);
  - }
  -
  };
  #endif // BITCOIN_PRIMITIVES_TRANSACTION_H
  