As noted by @onobc we have condition [here](https://github.com/spring-projects/spring-boot/blob/5e52468e83da9fdb9c519605e9626462e4aeb50a/spring-boot-project/spring-boot-tracing/src/main/java/org/springframework/boot/tracing/autoconfigure/zipkin/ZipkinTracingAutoConfiguration.java#L86) but not [here](https://github.com/spring-projects/spring-boot/blob/5e52468e83da9fdb9c519605e9626462e4aeb50a/spring-boot-project/spring-boot-tracing/src/main/java/org/springframework/boot/tracing/autoconfigure/zipkin/ZipkinTracingAutoConfiguration.java#L64)
