tdf#165748 re-save state of portrait/landscape buttons on apply

Change-Id: I7e525d41ce7b46c5086e3ef2112a74485cd46793
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/183273
Reviewed-by: Oliver Specht <oliver.specht@cib.de>
Tested-by: Jenkins

cui/source/tabpages/page.cxx

@@ -786,6 +786,8 @@ bool SvxPageDescPage::FillItemSet( SfxItemSet* rSet )
     {
         aPage.SetLandscape(bChecked);
         bMod = true;
+        m_xLandscapeBtn->save_state();
+        m_xPortraitBtn->save_state();
     }
 
     //Get the NumType value