sfx2: silence warning in SfxObjectShell::CopyStoragesOfUnknownMediaType()

I guess the intention is to catch all "own" formats, and Base is just
missing from that list.

Change-Id: I064068c2ab17db9109a9a4681775ba8d18292292

sfx2/source/doc/objstor.cxx

@@ -3484,6 +3484,7 @@ bool SfxObjectShell::CopyStoragesOfUnknownMediaType( const uno::Reference< embed
                         case SotClipboardFormatId::STARCALC_8:
                         case SotClipboardFormatId::STARCHART_8:
                         case SotClipboardFormatId::STARMATH_8:
+                        case SotClipboardFormatId::STARBASE_8:
                             break;
 
                         default: