Unused since commit 2c8fe2e7
"update unusedmethods plugin to deal with constructors"
where I removed a unused SfxDockingWindow constructor.
And in that case, the helpid was only being used to assign
the window a UniqueId.

Change-Id: I148e424424fcf08449440b83a8600071b39d7a07
Reviewed-on: https://gerrit.libreoffice.org/35554Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>