Fix WebSocket notifications

Ignore a missing `id` query param; it's unclear what this ID represents,
but it wasn't being used in the existing bitwarden_rs code, and no longer
seems to be sent in the latest versions of the official clients.

src/api/notifications.rs

@@ -152,6 +152,9 @@ impl WSHandler {
 impl Handler for WSHandler {
     fn on_open(&mut self, hs: Handshake) -> ws::Result<()> {
         // Path == "/notifications/hub?id=<id>==&access_token=<access_token>"
+        //
+        // We don't use `id`, and as of around 2020-03-25, the official clients
+        // no longer seem to pass `id` (only `access_token`).
         let path = hs.request.resource();
 
         let (_id, access_token) = match path.split('?').nth(1) {
@@ -170,10 +173,11 @@ impl Handler for WSHandler {
 
                 match (id, access_token) {
                     (Some(a), Some(b)) => (a, b),
-                    _ => return self.err("Missing id or access token"),
+                    (None, Some(b)) => ("", b), // Ignore missing `id`.
+                    _ => return self.err("Missing access token"),
                 }
             }
-            None => return self.err("Missing query path"),
+            None => return self.err("Missing query parameters"),
         };
 
         // Validate the user