Fix typo in location of spring cloud stream docs

Author: markpollack

spring-cloud-dataflow-docs/src/main/asciidoc/index.adoc

@@ -11,7 +11,7 @@ Sabby Anandan; Marius Bogoevici; Eric Bottard; Mark Fisher; Ilayaperumal Gopinat
 
 :spring-cloud-dataflow-docs: https://docs.spring.io/spring-cloud-dataflow/docs/{project-version}/reference
 :spring-cloud-dataflow-docs-current: https://docs.spring.io/spring-cloud-dataflow/docs/current-SNAPSHOT/reference/html/
-:spring-cloud-stream-docs: httsp://docs.spring.io/spring-cloud-stream/docs/current/reference/htmlsingle/index.html
+:spring-cloud-stream-docs: https://docs.spring.io/spring-cloud-stream/docs/current/reference/htmlsingle/index.html
 :spring-boot-version: 1.5.13.RELEASE
 :spring-boot-docs-reference: https://docs.spring.io/spring-boot/docs/1.5.13.RELEASE/reference
 :github-repo: spring-cloud/spring-cloud-dataflow