Jolie 1.12.4 is released!

This release is identical to v1.12.3 beside the following minor bug-fixes/improvements.

Changelog

• fixed HTTP content-negotiation on aggregated services (original request's context) (#580)
• fixed JSON escaping: slashes / should not be escaped by backslash \ (#588)

Full Changelog: v1.12.3...v1.12.4