allow firehose url with xrpc endpoint

src/views/stream.tsx

···
       url = url.concat("?");
     } else {
       url = formData.get("instance")?.toString() ?? "wss://bsky.network";
+      url = url.replace("/xrpc/com.atproto.sync.subscribeRepos", "");
+      if (!url.startsWith("wss://") && !url.startsWith("ws://")) url = "wss://" + url;
     }
 
     const collections = formData.get("collections")?.toString().split(",");