Simplify numShards and containsShards implementations in Routing
Simplify numShards and containsShards implementations in Routing

Removes the `isEmpty` checks, as they're kinda redundant and don't
necessarily improve performance.

EvilMcJerkface/crate,crate/crate,crate/crate,EvilMcJerkface/crate,EvilMcJerkface/crate,crate/crate