Fix default keystone branch for kitchen tests

Related: PROD-34126
Change-Id: I6f41944ad96417a56715a1c9ee17456d7152aaf9
diff --git a/.kitchen.yml b/.kitchen.yml
index 845ea20..de97c7e 100644
--- a/.kitchen.yml
+++ b/.kitchen.yml
@@ -18,7 +18,7 @@
     - name: keystone
       repo: git
       source: https://gerrit.mcp.mirantis.com/salt-formulas/keystone
-      branch: <%=ENV['GERRIT_BRANCH'] || 'master' %>
+      branch: <%=ENV['GERRIT_BRANCH'] || 'release/2019.2.0' %>
     - name: linux
       repo: git
       source: https://gerrit.mcp.mirantis.com/salt-formulas/linux