Enabling build of stitching when CUDA is available

Without proposed change, module throws build error regarding missing `opencv2/cudaimgproc.hpp`

Author: adamrankin

modules/stitching/CMakeLists.txt

@@ -9,5 +9,5 @@ if(BUILD_SHARED_LIBS AND BUILD_opencv_world AND OPENCV_WORLD_EXCLUDE_EXTRA_MODUL
   set(STITCHING_CONTRIB_DEPS "")
 endif()
 ocv_define_module(stitching opencv_imgproc opencv_features2d opencv_calib3d opencv_flann
-                  OPTIONAL opencv_cudaarithm opencv_cudawarping opencv_cudafeatures2d opencv_cudalegacy ${STITCHING_CONTRIB_DEPS}
+                  OPTIONAL opencv_cudaarithm opencv_cudawarping opencv_cudafeatures2d opencv_cudalegacy opencv_cudaimgproc ${STITCHING_CONTRIB_DEPS}
                   WRAP python)