The error returned by DecodeConfig was changed in
b6d58d749c and caused this to regress.
Allow empty request bodies for this endpoint once again.
Signed-off-by: Cory Snider <csnider@mirantis.com>
(cherry picked from commit 967c7bc5d3)
Signed-off-by: Cory Snider <csnider@mirantis.com>