Since the related change, object-reconstructor gathers the local devices
for ec policy via get_local_devices method but the method causes TypeError when
attempting *reduce* for empty set list. the list can be empty when no EC config
found in swift.conf.
This patch fixes the get_local_devices to return empty set even when no ec config
in swift.conf without errors.
Co-Authored-By: Kirill Zaitsev <k.zaitsev@me.com>
Change-Id: Ic121fb547966787a43f9eae83c91bb2bf640c4be
Related-Change: 701a172afac37229b85ea762f20428f6f422d29b
Closes-Bug: #1707595
45cc1d02d0