@ServletComponentScan does not work with a component index
when ServletComponentRegisteringPostProcessor add @WebServlet, it requires an ScannedGenericBeanDefinition from an ClassPathScanningCandidateComponentProvider.

it works fine without Context-Indexer but wrong with Context-Indexer.
ClassPathScanningCandidateComponentProvider will return an AnnotatedGenericBeanDefinition, when their is an spring.components file.

