Fixed branch-regexp for voltha-2.8 patchset verification jobs

Change-Id: I28d80a025513df39e8dc2debd616248b8cba8465
diff --git a/jjb/verify/voltha-go.yaml b/jjb/verify/voltha-go.yaml
index 95faaed..05125b7 100644
--- a/jjb/verify/voltha-go.yaml
+++ b/jjb/verify/voltha-go.yaml
@@ -11,7 +11,7 @@
       - 'verify-voltha-go-jobs-voltha-2.8':
           name-extension: '-voltha-2.8'
           override-branch: 'voltha-2.8'
-          branch-regexp: '{kind-voltha-regexp}'
+          branch-regexp: '^voltha-2.8$'
       - 'verify-voltha-go-jobs-master':
           branch-regexp: '^master$'
       - 'publish-voltha-go-jobs':