tdf#118578 sw: allow inserting only TextDocument

There are 3 sw document services: TextDocument, WebDocument and
GlobalDocument.

The current logic in SwView::InsertDoc() and
SwView_Impl::StartDocumentInserter() is to request a filter with the
same document service as the existing target document, so you can insert
only a GlobalDocument into a GlobalDocument, which doesn't make much
sense.

As it happens there are 2 different HTML import filters: "HTML" and
"HTML (StarWriter)", the latter using the TextDocument service.

So just hard-code to allow TextDocument regardless of the target
document.

(regression from 805fd1ca34)

Change-Id: I7dc0dd4789fba8b61625ca8eae74a864aea383b0
Reviewed-on: https://gerrit.libreoffice.org/57193
Tested-by: Jenkins
Reviewed-by: Michael Stahl <Michael.Stahl@cib.de>

sw/source/uibase/uiview/view2.cxx

@@ -2093,7 +2093,8 @@ long SwView::InsertDoc( sal_uInt16 nSlotId, const OUString& rFileName, const OUS
     else
     {
         m_pViewImpl->StartDocumentInserter(
-            pDocSh->GetFactory().GetFactoryName(),
+            // tdf#118578 allow inserting any Writer document except GlobalDoc
+            SwDocShell::Factory().GetFactoryName(),
             LINK( this, SwView, DialogClosedHdl ),
             nSlotId
         );