conf: storage: Fix duplicate check for gluster pools
    
    The pool name has to be the same too to warrant rejecting a pool
    definition as duplicate. This regression was introduced in commit
    2184ade3a0546b915252cb3b6a5dc88e9a8d2ccf.
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1236438