fabric-tna: build against main as default branch instead of master

Change-Id: I3cfe0693371e88fc4b0e069b41b8fcda046a42f0
diff --git a/jjb/repos/fabric-tna.yaml b/jjb/repos/fabric-tna.yaml
index a4acf71..5e6f3c3 100644
--- a/jjb/repos/fabric-tna.yaml
+++ b/jjb/repos/fabric-tna.yaml
@@ -13,7 +13,7 @@
 
     jobs:
       - 'fabric-tna-jobs':
-            stream: 'master'
+            stream: 'main'
 
 - job-group:
     name: 'fabric-tna-jobs'