Comment 'man_pages' config in conf.py
Comment 'man_pages' config in conf.py

Comment 'man_pages' config in conf.py to avoid the warning "no
'man_pages' config value found; no manual pages will be written"
when building docs with "tox -e docs".

Change-Id: I9f7920530e848d8e13dc74889794e79531894329

openstack/searchlight,openstack/searchlight,openstack/searchlight