jsonrpc: Image_reconcileVolumeChain

Align naming between API.py and schema.

Change-Id: Iadd13463c28ea8ebd0887fef2e45af4ea6e37d4d
Signed-off-by: pkliczewski <piotr.kliczewski@gmail.com>
Reviewed-on: http://gerrit.ovirt.org/35530
Reviewed-by: Adam Litke <alitke@redhat.com>