It looks like this was never working because the function call supplied
to many parameters.
Fix by removing the additional and unnecessary null parameter.
I would keep this change after the PF4 changes of the buildset page
since it otherwise might result in some awkward behaviour due to the
different tabs and their contents.
Change-Id: I6fa62343a22d7a54e85a7e8d0babdabdc08b6352