Update rust version in `lcli` Dockerfile (#2876)
Update rust version in `lcli` Dockerfile (#2876)

The `lcli` docker build was no longer working on the old rust version

Co-authored-by: realbigsean <73195634d109c8d8533133f62102413ab6837100@gmail.com>

sigp/lighthouse,sigp/lighthouse,sigp/lighthouse,sigp/lighthouse