dashboard/app: select only normal builds during reporting

Don't select job builds during reporting,
they contain random git repositories.

dashboard/app/entities.go

@@ -276,6 +276,7 @@ func lastManagerBuild(c context.Context, ns, manager string) (*Build, error) {
 	_, err := datastore.NewQuery("Build").
 		Filter("Namespace=", ns).
 		Filter("Manager=", manager).
+		Filter("Type=", BuildNormal).
 		Order("-Time").
 		Limit(1).
 		GetAll(c, &builds)

dashboard/app/index.yaml

@@ -31,6 +31,7 @@ indexes:
   properties:
   - name: Namespace
   - name: Manager
+  - name: Type
   - name: Time
     direction: desc