Fix pep8 violations in message/object.py
Fix pep8 violations in message/object.py

Change-Id: I1e5644421c6b90f593405b23058af2d28a36d9af
Signed-off-by: Thanh Ha <09ea4d3a79c8bee41a16519f6a431f6bc0fd8d6f@linuxfoundation.org>

opendaylight/bgpcep,bigdataops/bgpcep,inocybe/odl-bgpcep,inocybe/odl-bgpcep,bigdataops/bgpcep