[Pkg-rust-maintainers] Bug#1007026: rust-weedle - needs nom 5

[Peter Green]

reopen 1007026
thanks

>   * Revert to nom 4, porting to nom 7 seems to be non-trivial and I do not
>     want to further increase the proliferation of nom versions in Debian.

As I said in the initial mail, I did indeed patch weedle to revert
to nom 4. However in doing so I caused an API break. As such I don't
think this package in it's current state is fit for release.