Bump mtui from 45ff8d0 to 6c07b11

Bumps [mtui](https://github.com/minetest-go/mtui_mod) from `45ff8d0` to `6c07b11`.
- [Commits](minetest-go/mtui_mod@45ff8d0...6c07b11)

---
updated-dependencies:
- dependency-name: mtui
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>