Previously, only SmartEndpointInterceptor instances declared as bean
were considered by AbstractEndpointMapping. Given that it extends from
EndpointInterceptor, this meant that adding them using the regular
setEndpointInterceptor mean they were not considered as such, that is
added irrespective of their `shouldIntercept` contract.
This commit considers both list as holding SmartEndpointInterceptor
instances. As a result, these can now be added using regular hook
points, such as WsConfigurer.
Closes gh-1130
daccb0db6d