Fixing the re-apply issue

[PapeCoding]

Fixing the issue, where reapplying a preset or re-enabling the LiveLink source broke the connection. This was referred to in a note on the test project:

Note: Currently the plugin cannot handle a restart of the Live Link source. If the DTrack Live Link source is already set up (manually or automatically), starting a new game in Play-in-Editor mode will not work with the preset mechanism described above. A simple workaround is to restart the Editor in this case, and generally to disconnect the Apply to Client node from the execution path as long as you do not need a packaged build.

This PR is based on the changes from #4.

Kind regards,
the Virtual Reality and Immersive Visualization Group of RWTH Aachen University