Remove IteratorHelpers from CMake

Author: franzpoeschel

CMakeLists.txt

@@ -420,7 +420,6 @@ set(CORE_SOURCE
         src/helper/list_series.cpp
         src/snapshots/ContainerImpls.cpp
         src/snapshots/ContainerTraits.cpp
-        src/snapshots/IteratorHelpers.cpp
         src/snapshots/IteratorTraits.cpp
         src/snapshots/RandomAccessIterator.cpp
         src/snapshots/Snapshots.cpp