Changelog:
==========
Fixed regression caused by #8133 where the pickle format for mutable attributes
was changed, without a fallback to recognize the old format, causing in-place
upgrades of SQLAlchemy to no longer be able to read pickled data from previous
versions. A check plus a fallback for the old format is now in place.
Signed-off-by: Zheng Ruoqin <zhengrq.fnst@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
