Resolving crash in wizards fdo#59931 by NULL checking

Change-Id: Iccc3f3b2913f21a3831ce55c706aa4dd1da53ad6
Reviewed-on: https://gerrit.libreoffice.org/1909Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>

svtools/source/control/roadmap.cxx

@@ -700,7 +700,10 @@ namespace svt
             SetFont( aFont );
             RoadmapTypes::ItemId curItemID = GetCurrentRoadmapItemID();
             RoadmapItem* pLabelItem = GetByID( curItemID );
-            pLabelItem->ToggleBackgroundColor(rStyleSettings.GetHighlightColor());
+            if (pLabelItem != NULL)
+            {
+                pLabelItem->ToggleBackgroundColor(rStyleSettings.GetHighlightColor());
+            }
             Invalidate();
         }
     }