fix: system model setting missing space between buttons (#6912)

web/app/components/header/account-setting/model-provider-page/system-model-selector/index.tsx

@@ -249,6 +249,7 @@ const SystemModel: FC<SystemModelSelectorProps> = ({
               {t('common.operation.cancel')}
             </Button>
             <Button
+              className='ml-2'
               variant='primary'
               onClick={handleSave}
               disabled={!isCurrentWorkspaceManager}