chart2: Add missing include

Change-Id: I06eacfd944cf4ae7eef44900352b958e08f91b42
Reviewed-on: https://gerrit.libreoffice.org/18522Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: David Ostrovsky <david@ostrovsky.org>

chart2/qa/unit/common_functor_test.cxx

@@ -15,6 +15,7 @@
 #include <com/sun/star/uno/Any.h>
 #include <rtl/ustring.hxx>
 
+#include <iterator>
 #include <vector>
 
 #include "CommonFunctors.hxx"