Fixing header

Author: ryanjbaxter

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

@@ -1661,7 +1661,7 @@ The following sections show how each one works:
 * <<spring-cloud-config-serving-plain-text-git-svn-native-backends>>
 * <<spring-cloud-config-serving-plain-text-aws-s3>>
 
-== Serving Binary Files
+=== Serving Binary Files
 
 In order to serve binary files from the config server you will need to send an `Accept` header of `application/octet-stream`.