Resolves: fdo#70571 don't crash when clicking link in toc

when link is in a toc, and Cursor in protected areas is
disabled, causing the cursor to leap before the toc
before trying to see what's under the cursor in order
to jump to it

Change-Id: Iaf348e3621df02628b4d2ac8c1165df7082237ed

sw/source/ui/docvw/edtwin.cxx

@@ -4506,7 +4506,7 @@ void SwEditWin::MouseButtonUp(const MouseEvent& rMEvt)
                             }
                             else
                             {
-                                if ( bExecHyperlinks )
+                                if ( bExecHyperlinks && aCntntAtPos.aFnd.pAttr )
                                     rSh.ClickToINetAttr( *(SwFmtINetFmt*)aCntntAtPos.aFnd.pAttr, nFilter );
                             }