Remove duplicate recgroups from the list in the schedule editor.

Fixes #9173

Signed-off-by: Stuart Morgan <smorgan@mythtv.org>

mythtv/programs/mythfrontend/scheduleeditor.cpp

@@ -771,6 +771,7 @@ void StoreOptEditor::Load()
     }
 
     groups.sort();
+    groups.removeDuplicates();
     for (it = groups.begin(); it != groups.end(); ++it)
     {
         label = tr("Include in the \"%1\" recording group");