Investigate why latest magmaProxy.jar causes problems

[Gama11]

At least with my testing environment, the updated magmaProxy.jar from 86ce99a broke the tool (agents not starting anymore). I reverted it for now in ae94587 - need to investigate what the issue is.

[Gama11]

I managed to identify the breaking commit as magmaOffenburg/magmaProxy@6a427e7.