node-proxy: fix RedFishClient.logout() method

node-proxy: fix RedFishClient.logout() method

the endpoint passed down to util.query() is wrong:
is passes the full url (scheme://addr:port/path) where it should only
pass the path. The cause is that RedFishClient.login() basically stores
the value of the Location header in `self.location`.

The consequence of this is that it makes the client unable to properly logout.

Fixes: https://tracker.ceph.com/issues/64894
Signed-off-by: Guillaume Abrioux <gabrioux@ibm.com>