adding small delay in creating publisher

[vishrutsingh1]

Small delay is added in the 'mqtt2primitive' function because whenever the first message is received, it creates a publisher. Since there is no delay in creating a publisher and publishing a message, the first message is always missed on the ROS topic. Adding a delay in creating the publisher solved the problem.

[lreiher]

Thank you for the contribution!

Is there perhaps a better way to wait for the publisher to be ready? The 200ms seems arbitrary. Maybe there is a dedicated function/attribute of the publisher.

[JayHerpin]

If its problematic for the first message to be missed, perhaps a better roption is to support explicitly setting the QoS?

[JayHerpin]

I believe that this #61 makes this unnecessary if you are willing to configure the types explicitly

[lreiher]

These changes should be made obsolete by #61, thank you very much, anyway! Hopefully your problem is resolved now!