Add explicit constructor

[adamoutler]

Fixes a message with this class when modularized
se/vidstige/jadb/Subprocess.java:[23,8] class se.vidstige.jadb.Subprocess in exported package se.vidstige.jadb declares no explicit constructors, thereby exposing a default constructor to clients of module my.module.

[vidstige]

Thanks for your contribution. The warning seems weird, where did you see this warning?

[adamoutler]

Java 11. I converted, modularized, and imported to my codebase before you added the changes for automodule. I'm contributing back compatible changes.

You will eventually want to upgrade to Java 11, even if only in a docker container on Actions on GitHub. Minor changes are needed for compatibility and like this, but the major item is the module-info.java. Aside from the module-info, it's just a bunch of lint and syntactic faux pas that have no bearing on operation, but make it more compatible with lint checks.

[vidstige]

I see. Thanks for the initiative and your contribution. I'm currently not working at all on this so any moves to new Java versions is entirely dependent on contributors like yourself. PRs welcome!

For the future - Avoid comments that are not very helpful like // empty to keep the code clean and easy to read.

[vidstige]

I think the public Subprocess(){} constructor needs to be inside the class Subprocess? The build is currently failing.

Please amend the commit. 🙏