Fix typo in env vars for CC pipelines

Change-Id: Ide6ecc01c677ada4163aa31eb5b7db039be33f5e
diff --git a/test-cookiecutter-reclass.groovy b/test-cookiecutter-reclass.groovy
index d93a618..bd3373c 100644
--- a/test-cookiecutter-reclass.groovy
+++ b/test-cookiecutter-reclass.groovy
@@ -49,7 +49,7 @@
 gerritDataRSHEAD = [:]
 gerritDataRS = [:]
 gerritDataRS << gerritConData
-gerritDataRS['gerritBranch'] = env.RECLASS_MODEL_BRANCH ?: 'master'
+gerritDataRS['gerritBranch'] = env.RECLASS_SYSTEM_BRANCH ?: 'master'
 gerritDataRS['gerritRefSpec'] = env.RECLASS_SYSTEM_GIT_REF ?: null
 gerritDataRS['gerritProject'] = 'salt-models/reclass-system'