SuperBuild: update patch for opencv

SuperBuild/patches/OPENCV/opencv-1-install-prefix-win.diff

-diff -burN opencv-2.4.13.2.orig/CMakeLists.txt opencv-2.4.13.2/CMakeLists.txt
---- opencv-2.4.13.2.orig/CMakeLists.txt	2017-04-25 14:05:11.148414719 +0200
-+++ opencv-2.4.13.2/CMakeLists.txt	2017-04-25 14:06:05.944787632 +0200
-@@ -290,7 +290,9 @@
+diff -burN opencv-3.4.1.orig/CMakeLists.txt opencv-3.4.1/CMakeLists.txt
+--- opencv-3.4.1.orig/CMakeLists.txt	Wed Sep 26 15:10:50 2018
++++ opencv-3.4.1/CMakeLists.txt	Wed Sep 26 15:12:40 2018
+@@ -373,7 +373,7 @@
  
- if(WIN32)
+ if(WIN32 AND CMAKE_HOST_SYSTEM_NAME MATCHES Windows)
    if(DEFINED OpenCV_RUNTIME AND DEFINED OpenCV_ARCH)
--    set(OpenCV_INSTALL_BINARIES_PREFIX "${OpenCV_ARCH}/${OpenCV_RUNTIME}/")
-+    #OTB PATCH [BEGIN]
-+    set(OpenCV_INSTALL_BINARIES_PREFIX "") # "${OpenCV_ARCH}/${OpenCV_RUNTIME}/")
-+    #OTB PATCH [END]
+-    ocv_update(OpenCV_INSTALL_BINARIES_PREFIX "${OpenCV_ARCH}/${OpenCV_RUNTIME}/")
++    ocv_update(OpenCV_INSTALL_BINARIES_PREFIX "") #${OpenCV_ARCH}/${OpenCV_RUNTIME}/")
    else()
      message(STATUS "Can't detect runtime and/or arch")
-     set(OpenCV_INSTALL_BINARIES_PREFIX "")
+     ocv_update(OpenCV_INSTALL_BINARIES_PREFIX "")