How to justify motivations for a second master?
I don't find your justification wise enough for a second master degree in distributed systems and networks. Moreover, I don't find a real target behind the second master degree other than getting associated with professors and the country.

If your prime purpose is to learn new stuff, you don't need a second academic degree which is very similar to the one that you already have. You can learn on your own. Moreover, you could directly apply for a research degree (say Ph.D.) in Germany instead. This would definitely make more sense. Unless you have some serious career goals to pursue on the specified courses, you should not do it. In my university, my colleagues who have Ph.D. in software engineering are now doing serious research in IoT, Distributed Systems, and Network security.

Ask yourself this question: If you get interested in computational economics after 2 years, would you again apply for a masters degree in the same field?