remote_node_ip: use same return signature for both branches

remote_node_ip: use same return signature for both branches

We have two return statements in the remote_node_ip submethod, one
checked if we are in list context and adapt the returning values
accordingly and one just returned a list, independent of the
context.
Adapt the second one and check the context there.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>