Merge pull request #6241 from RosettaCommons/roccomoretti/interactive_none_preset_crash
[Foldit] Fix crash when selecting None preset.
The None preset was being built as a base class object, but the actual application needed to dynamic cast to a Standalone-level object. This resulted in a nullpointer when you tried to activate the None preset.
Now when you select "None", the actual view doesn't change, but you no longer have the preset selected.
RELEASE NOTES: Fix crash when None preset is selected.