Bug#1136348: needs to be updated to 1.2

[Daniel Baumann]

Package: rust-mio
Severity: serious

Hi,
other packages in the archive, such as rust-tokio 1.52, declare 
dependencies on rust-mio 1.2.

Please update rust-mio to 1.2 to unbreak the rust-tokio 
(build-)dependecy chain.

Regards,
Daniel