client: Fix capitalization of comment (#54610)

This is less of an actual fix than more a test for the merge queue.

Release Notes:

- N/A

crates/client/src/user.rs

@@ -220,7 +220,7 @@ impl UserStore {
                 let weak = Arc::downgrade(&client);
                 drop(client);
                 while let Some(status) = status.next().await {
-                    // if the client is dropped, the app is shutting down.
+                    // If the client is dropped, the app is shutting down.
                     let Some(client) = weak.upgrade() else {
                         return Ok(());
                     };