Fixed libtool linking for iOS build.

Emgu.CV.Extern/CMakeLists.txt

@@ -4137,7 +4137,7 @@ ELSEIF (IOS)
 	  COMPONENT emgucv_binary) 	 
   ENDIF()
   #MESSAGE(STATUS "<<<<<< IOS_RELEASE_FOLDER: ${IOS_RELEASE_FOLDER} >>>>>>") 
-  SET(LIBTOOL_LINKING_COMMAND libtool -static -o ${CMAKE_SOURCE_DIR}/libs/iOS/${IOS_RELEASE_FILENAME} bin${UNMANAGED_LIBRARY_OUTPUT_SUBFOLDER}/Release/*.a opencv/3rdparty/lib/Release/*.a ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/Release/*.a)
+  SET(LIBTOOL_LINKING_COMMAND libtool -static -arch_only ${IOS_ARCH} -o ${CMAKE_SOURCE_DIR}/libs/iOS/${IOS_RELEASE_FILENAME} bin${UNMANAGED_LIBRARY_OUTPUT_SUBFOLDER}/Release/*.a opencv/3rdparty/lib/Release/*.a ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/Release/*.a)
   IF (EMGU_CV_WITH_TESSERACT)
      LIST(APPEND LIBTOOL_LINKING_COMMAND libs/Release/*.a)
   ENDIF()
@@ -4148,7 +4148,7 @@ ELSEIF (IOS)
     POST_BUILD
     COMMAND ${LIBTOOL_LINKING_COMMAND}
     WORKING_DIRECTORY "${CMAKE_BINARY_DIR}"
-    COMMENT "Linking target for ${IOS_ARCH}")
+    COMMENT "Linking target for ${IOS_ARCH} using command: ${LIBTOOL_LINKING_COMMAND}")
     
   SET(IPHONEOS_STATIC_LIB_FILE ${CMAKE_SOURCE_DIR}/libs/iOS/libcvextern_iphoneos.a)
   SET(IPHONESIMULATOR_STATIC_LIB_FILE ${CMAKE_SOURCE_DIR}/libs/iOS/libcvextern_simulator.a)