fix: avoid creation unnnecessary stream for static sockjs file (#4482)

Author: alexander-akait

lib/Server.js

@@ -1964,12 +1964,9 @@ class Server {
       (req, res) => {
         res.setHeader("Content-Type", "application/javascript");
 
-        const { createReadStream } = fs;
         const clientPath = path.join(__dirname, "..", "client");
 
-        createReadStream(
-          path.join(clientPath, "modules/sockjs-client/index.js")
-        ).pipe(res);
+        res.sendFile(path.join(clientPath, "modules/sockjs-client/index.js"));
       }
     );