Bug#956266: rustc: build-depends-indep on old version of wasi-libc

[peter green]

Package: rustc
Version: 1.41.1+dfsg1-1
Severity: serious

rustc build-depends-indep on wasi-libc (<= 0.0~git20191220.a280fea++) but 
unstable (and soon if not already testing) has version 0.0~git20200114.1fad338-1