fdo#57079: SvxSuperContourDlg: unregister configuration listener

... in destructor.  Otherwise it will access freed memory when
eventually called.  This crashes since OOo 3.2 but no idea why it would
appear to not crash in earlier versions.

Change-Id: Ie3ab7ddf19fb1086f0b7d824555ab6b063e2b9ad

svx/source/dialog/_contdlg.cxx

@@ -264,6 +264,8 @@ SvxSuperContourDlg::SvxSuperContourDlg( SfxBindings *_pBindings, SfxChildWindow
 
 SvxSuperContourDlg::~SvxSuperContourDlg()
 {
+    SvtMiscOptions aMiscOptions;
+    aMiscOptions.RemoveListenerLink( LINK(this, SvxSuperContourDlg, MiscHdl) );
 }
 
 // Resize methods