Tidy up the code (#12116)

Small follow-ups for https://github.com/zed-industries/zed/pull/12063
and https://github.com/zed-industries/zed/pull/12103

Release Notes:

- N/A

crates/collab/src/rpc.rs

@@ -2442,7 +2442,7 @@ async fn rename_dev_server(
         .rename_dev_server(
             dev_server_id,
             &request.name,
-            &request.ssh_connection_string,
+            request.ssh_connection_string.as_deref(),
             session.user_id(),
         )
         .await?;