Revert "Build oauth plugin against gerrit stable-3.{9,10} branches"

This reverts commit 92b3695c00b051e0a6eddc24d9404ecda8a4339a.

Reason for revert: I haven't archived stable-3.7 yet, so we need this back on the Gerrit-CI

Change-Id: I19748a49933665a78e56e333d9f15970287e13cb
diff --git a/jenkins/gerrit-bazel-plugin-oauth.yaml b/jenkins/gerrit-bazel-plugin-oauth.yaml
index cb66f9d..3262db3 100644
--- a/jenkins/gerrit-bazel-plugin-oauth.yaml
+++ b/jenkins/gerrit-bazel-plugin-oauth.yaml
@@ -9,3 +9,4 @@
             - stable-3.10
             - stable-3.9
             - stable-3.8
+            - stable-3.7