Bug#946019: rust-rusty-tags build-depends on nonexistent virtual package.

[peter green]

Package: rust-rusty-tags
Version: 3.5.1-1
Severity: serious
Tags: bullseye, sid

rust-rusty-tags build-depends on librust-dirs-1+default-dev which is no longer 
provided by rust-dirs. It seems to have been replaced by 
librust-dirs-2+default-dev.