Reference map could not be read

[estrogently]

af914d3 broke refmap generation for me. Inside the jar, the file starts with an uppercase M, but Fabric tries to find it with a lowercase m.

Can’t open a pull request here but here’s how I fixed it for myself: https://github.com/estrogently/mambience/commit/a4d13f7ecfade552b1f2f219980a7ff0d7e45f7b (TL;DR: reverted af914d3, and lowercased the archive base name).