Note on host in ./doc/radosgw/config.rst

Some people have configured host with a FQDN or an IP
which prevents /etc/init.d/radosgw start to launch the daemon.
Edit rgw keystone url in ./doc/radosgw/config.rst

Won't work with the public port, it needs to be the admin port.
Edit endpoint-create in ./doc/radosgw/config.rst

internalurl and adminurl are mandatory. Typo in publicurl.
Merge pull request #38 from alram/master

Fixes in ./docs/radosgw/config.rst