Update attributes.asciidoc (#2365)

Author: bmorelli25

shared/attributes.asciidoc

@@ -427,12 +427,3 @@ Legacy definitions
 :apm-overview-ref-70:  https://www.elastic.co/guide/en/apm/get-started/7.0
 :apm-overview-ref-m:   https://www.elastic.co/guide/en/apm/get-started/master
 :infra-guide:          https://www.elastic.co/guide/en/infrastructure/guide/{branch}
-///////
-Temporarily reroute APM Agent links to the new APM documentation book
-///////
-ifeval::["{branch}"=="7.17"]
-:apm-server-ref:       {apm-guide-ref}
-:apm-server-ref-v:     {apm-guide-ref}
-:apm-overview-ref-v:   {apm-guide-ref}
-:apm-get-started-ref:  {apm-guide-ref}
-endif::[]