fix(store-gateway): don't log to stdout

Since we're not execing the radosgw daemon, its view of /dev/stdout
is not really stdout, resulting in the logs being eaten. Now they'll
at least be on the filesystem should debugging be necessary.

store/base/templates/ceph.conf

@@ -17,4 +17,3 @@ log file = /dev/stdout
 host = deis-store-gateway
 keyring = /etc/ceph/ceph.client.radosgw.keyring
 rgw socket path = /var/run/ceph/ceph.radosgw.gateway.fastcgi.sock
-log file = /dev/stdout