Remove dead code.

While it is true that one *could* call ContainerBroker.get_info() with
include_metadata=True, it is also true that nobody actually does.

It's also true that the code path taken when include_metadata=True is
broken in the case of non-ASCII metadata keys
(e.g. X-Container-Meta-☃: snowman), so leaving it around is just
asking for future pain.

Change-Id: I4931add4b8fb7c4f57820e52f182c21040d8db10
Merge "Remove dead code."