Replace 2.1 nightly tests with 2.2

Change-Id: I75d2dcb916b4bf694ce6c09e9e54d5299f00d52e
diff --git a/jjb/OnosSystemTest/onos-test-freestyle.yaml b/jjb/OnosSystemTest/onos-test-freestyle.yaml
index 00c61c1..1d2cbc7 100644
--- a/jjb/OnosSystemTest/onos-test-freestyle.yaml
+++ b/jjb/OnosSystemTest/onos-test-freestyle.yaml
@@ -568,7 +568,7 @@
 
     <<: *test-free-init-procedure-plate
 
-    sr-version-before-previous: '2.1'
+    sr-version-before-previous: '2.2'
     sr-version-previous: '1.15'
     sr-version-current: 'master'