Merge pull request #906 from ansible/revert-895-backport/890/release_2.1

Revert "[release_2.1] Switch project to squash-merge mode"

Reverts #895
This only needs to be defined in one branch.

Reviewed-by: Sam Doran <[email protected]>
Reviewed-by: None <None>

Author: ansible-zuul[bot]

.zuul.d/project.yaml

@@ -1,6 +1,5 @@
 ---
 - project:
-    merge-mode: squash-merge
     check:
       jobs: &id001
         - ansible-buildset-registry