Missing slash when generating link with context path

When generating a link to a method which is mapped without a leading slash (@RequestMapping("hello")), the mapping generated in AnnotationMappingDiscoverer#getMapping(Class<?>, Method) does not have a leading slash as well.

If the request does not contain a context path this is not a problem, but if it does context path and mapping are concatenated without a slash inbetween.

imo this could be fixed by adding the leading slash in AnnotationMappingDiscoverer#cleanup(), but this would of course be a breaking change, which causes two tests in AnnotationMappingDiscovererUnitTest to fail

For an example see this repository and the test in com.example.HateoasSlashExampleApplicationTests