"openstack overcloud ffwd-upgrade run" fails with package conflict issue if it is run after a previous failure.

Issue

• openstack overcloud ffwd-upgrade run fails with package conflict issue if it is run after a previous failure.

u'TASK [Cinder package update] ***************************************************',
 u'Friday 05 April 2019  12:59:38 +0530 (0:00:16.695)       0:08:56.126 ********** ',
 u'fatal: [labeng-cntl-0]: FAILED! => {"changed": true, "cmd": "yum -y update openstack-cinder*", "delta": "0:00:23.231597", "end": "2019-04-05 07:30:01.809118", "msg": "non-zero return code", "rc": 1, "start": "2019-04-05 07:29:38.577521", "stderr": "\
\
Transaction check error:\
  file /usr/lib/python2.7/site-packages/pyparsing.py from install of python2-pyparsing-2.1.10-3.el7ost.noarch conflicts with file from package pyparsing-2.0.7-1.el7ost.noarch\
  file /usr/lib/python2.7/site-packages/pyparsing.pyc from install of python2-pyparsing-2.1.10-3.el7ost.noarch conflicts with file from package pyparsing-2.0.7-1.el7ost.noarch\
  file /usr/lib/python2.7/site-packages/pyparsing.pyo from install of python2-pyparsing-2.1.10-3.el7ost.noarch conflicts with file from package pyparsing-2.0.7-1.el7ost.noarch\
\