fix for feature2d java wrappers as described in this post:…

fix for feature2d java wrappers as described in this post: http://answers.opencv.org/question/101675/surfsift-java-wrapper-for-opencv-3xosx-1011/

modules/xfeatures2d/CMakeLists.txt

 set(the_description "Contributed/Experimental Algorithms for Salient 2D Features Detection")
 ocv_define_module(xfeatures2d opencv_core opencv_imgproc opencv_features2d opencv_calib3d opencv_shape opencv_highgui opencv_videoio opencv_ml
-                  OPTIONAL opencv_cudaarithm WRAP python)
+                  OPTIONAL opencv_cudaarithm WRAP python java)