Moving kind-voltha sanity test from 2.5 to 2.6

Change-Id: I9f30ddcc4379f55f8f0844b1ad154a71ec1a4032
diff --git a/jjb/verify/kind-voltha.yaml b/jjb/verify/kind-voltha.yaml
index 0958d9f..e66be45 100644
--- a/jjb/verify/kind-voltha.yaml
+++ b/jjb/verify/kind-voltha.yaml
@@ -21,5 +21,5 @@
           pipeline-script: 'voltha-bbsim-tests.groovy'
       - 'voltha-patch-test':
           pipeline-script: 'voltha-bbsim-tests.groovy'
-          name-extension: '-2.5'
-          override-branch: 'voltha-2.5'
+          name-extension: '-2.6'
+          override-branch: 'voltha-2.6'