[checkrunner] fix using a custom_order by explicitly converting to list; See
@@ -1223,7 +1223,7 @@ class Spec(object):
order may contain "*check" otherwise, it is like *check is appended
to the end (Not done explicitly though).
"""
- stack = custom_order[:] if custom_order is not None else section.order[:]
+ stack = list(custom_order) if custom_order is not None else list(section.order)
if '*iterargs' not in stack:
stack.append('*iterargs')
stack.reverse()
