fixed warning: can't generate assignment operator

modules/flann/include/opencv2/flann/kdtree_index.h

@@ -314,6 +314,9 @@ public:
 
 private:
 
+	KDTreeIndex& operator=(const KDTreeIndex&);
+	KDTreeIndex(const KDTreeIndex&);
+
 
     void save_tree(FILE* stream, Tree tree)
     {

modules/flann/include/opencv2/flann/kmeans_index.h

@@ -596,6 +596,8 @@ public:
 
 private:
 
+	KMeansIndex& operator=(const KMeansIndex&);
+	KMeansIndex(const KMeansIndex&);
 
     void save_tree(FILE* stream, KMeansNode node)
     {

modules/flann/include/opencv2/flann/linear_index.h

@@ -54,6 +54,9 @@ class LinearIndex : public NNIndex<ELEM_TYPE>
 	const Matrix<ELEM_TYPE> dataset;
 	const LinearIndexParams& index_params;
 
+	LinearIndex(const LinearIndex&);
+	LinearIndex& operator=(const LinearIndex&);
+
 public:
 
 	LinearIndex(const Matrix<ELEM_TYPE>& inputData, const LinearIndexParams& params = LinearIndexParams() ) :