Fix regression in build-script

The regex patch introduced a regression where the summary was not
working due to not copying the images lists, but rather referencing it

This only happens when you do not use a regex to build, but instead
build all images

Change-Id: Ife0ef2d459248aa73af877313140b5392c05673c
Partially-Implements: blueprint build-script

kolla/cmd/build.py

@@ -299,7 +299,7 @@ class KollaWorker(object):
                         images_to_process.append(image)
                         added = True
         else:
-            images_to_process = self.images
+            images_to_process = list(self.images)
 
         self.tiers = list()
         while images_to_process: