fix: Update PubSub Example test

[maschad]

Closes #1540

[achingbrain]

Ah, whoops - I didn't see this sorry.

It's not necessary for node1 and node3 to be connected as node2 should relay messages to node3.

Instead we need to wait for node1 to know node2 is subscribed to the topic, and that node2 knows node3 is subscribed to the topic.

See the fix here: #1549

[maschad]

Ah, whoops - I didn't see this sorry.

It's not necessary for node1 and node3 to be connected as node2 should relay messages to node3.

Instead we need to wait for node1 to know node2 is subscribed to the topic, and that node2 knows node3 is subscribed to the topic.

See the fix here: #1549

Understood. I thought that node1 needed to also have node3 in it's subscriber list in order for the messages to be relayed to node3