Fix docs about @Configuration with @FeignClient (#1650)

docs/src/main/asciidoc/spring-cloud-netflix.adoc

@@ -942,7 +942,7 @@ public interface StoreClient {
 
 In this case the client is composed from the components already in `FeignClientsConfiguration` together with any in `FooConfiguration` (where the latter will override the former).
 
-WARNING: The `FooConfiguration` has to be `@Configuration` but take care that it is not in a `@ComponentScan` for the main application context, otherwise it will be used for every `@FeignClient`. If you use `@ComponentScan` (or `@SpringBootApplication`) you need to take steps to avoid it being included (for instance put it in a separate, non-overlapping package, or specify the packages to scan explicitly in the `@ComponentScan`).
+NOTE: `FooConfiguration` does not need to be annotated with `@Configuration`. However, if it is, then take care to exclude it from any `@ComponentScan` that would otherwise include this configuration as it will become the default source for `feign.Decoder`, `feign.Encoder`, `feign.Contract`, etc., when specified. This can be avoided by putting it in a separate, non-overlapping package from any `@ComponentScan` or `@SpringBootApplication`, or it can be explicitly excluded in `@ComponentScan`.
 
 NOTE: The `serviceId` attribute is now deprecated in favor of the `name` attribute.