[7.1][Docs] Backport: Change path to beats breaking changes file (#331) (#347)

* [Docs] Change path to beats breaking changes file (#331)

* [Docs] Change link to point to 7.1 breaking changes doc

Author: dedemorton

docs/en/install-upgrade/breaking.asciidoc

@@ -44,7 +44,7 @@ This list summarizes the most important breaking changes in Beats.
 For the complete list, go to {beats-ref}/breaking-changes.html[Beats breaking changes].
 
 
-include::{beats-repo-dir}/breaking.asciidoc[tag=notable-breaking-changes]
+include::{beats-repo-dir}/breaking-7.1.asciidoc[tag=notable-breaking-changes]
 
 
 [[elasticsearch-breaking-changes]]