Fix unaliasing workaround bug introduced in 1e83a31cc1.
Fix unaliasing workaround bug introduced in 1e83a31cc1.

The previous code assumed to_dict() works normally but it is hooked for both
_SnapshotForUser and _SnapshotForDimensions to change the properties. This
caused .populate() to fail.

TBR=csharp@chromium.org
BUG=

Review URL: https://codereview.appspot.com/91410043

pombreda/swarming,luci/luci-py,madecoste/swarming,madecoste/swarming,pombreda/swarming,madecoste/swarming,pombreda/swarming,madecoste/swarming,pombreda/swarming,luci/luci-py,luci/luci-py,luci/luci-py