ENH: Update ITKv5 to latest upstream.

Author: hjmjohnson

SuperBuild/External_ITKv5.cmake

@@ -40,7 +40,7 @@ if(NOT DEFINED ITK_DIR AND NOT ${CMAKE_PROJECT_NAME}_USE_SYSTEM_${proj})
 
   #set(${CMAKE_PROJECT_NAME}_${proj}_GIT_REPOSITORY ${git_protocol}://github.com/InsightSoftwareConsortium/ITK.git
   set(${CMAKE_PROJECT_NAME}_${proj}_GIT_REPOSITORY ${git_protocol}://github.com/hjmjohnson/ITK.git)
-  set(${CMAKE_PROJECT_NAME}_${proj}_GIT_TAG fe34d9caa5d98face1ef422afdfc05d71d38a68c ) #20180518 - GenericLabelmapInterpolator
+  set(${CMAKE_PROJECT_NAME}_${proj}_GIT_TAG 66737ee424063a391ad64bfc1ed8cbd96b10231b ) #20180518 - GenericLabelmapInterpolator
 
   set(EXTERNAL_PROJECT_OPTIONAL_CMAKE_CACHE_ARGS)