qvm-template: only ask for confirmation during install if something is being done

qubesadmin/tools/qvm_template.py

@@ -988,6 +988,9 @@ def install(
         for name in dl_list:
             override_tpls.append(name)
 
+        # Only confirm if we have something to do
+        # since confiming w/ an empty list is probably silly
+        if override_tpls:
             confirm_action(
                 'This will override changes made in the following VMs:',
                 override_tpls)