message: flann: add normal assignment operator for cvflann::any
diff: @@ -246,6 +246,12 @@ public:
  return assign(x);
  }
  + /// Assignment operator. Template-based version above doesn't work as expected. We need regular assignment operator here.
  + any& operator=(const any& x)
  + {
  + return assign(x);
  + }
  +
  /// Assignment operator, specialed for literal strings.
  /// They have types like const char [6] which don't work as expected.
  any& operator=(const char* x)
  