fix to cmake file exclusion list for mex cpps

list_exclude_from_build.cmake

@@ -1,6 +1,5 @@
 SET(list_exclude_from_build_SRC
 features/simplefeatures/matlab/CodebookRandomForestMex.cpp
-features/simplefeatures/matlab/HelperDataConversionMex.h
 features/simplefeatures/matlab/testHelperDataConversionMex.cpp
 )