Mantis #4450: DRR 'default refresh rate' setting can be enabled without setting a value from the dropdown menu. Fix and Update DRR Value for GUI Setting to avoid a crash after clicking on default button setting.
Fix DRR 'default' button: Restore default table values and set default refreshrate to ATSCHD when it has no value
Merge remote-tracking branch 'remotes/origin/BUG4450-DRR_default_refresh_rate_setting_can_be_enabled_without_setting_a_value_from_the_dropdown_menu'