refactor: simplify for loops to for...of in Server.js (#5496)

Author: noritaka1166

lib/Server.js

@@ -3123,10 +3123,7 @@ class Server {
     // always allow localhost host, for convenience
     // allow if value is in allowedHosts
     if (Array.isArray(allowedHosts) && allowedHosts.length > 0) {
-      for (let hostIdx = 0; hostIdx < allowedHosts.length; hostIdx++) {
-        /** @type {string} */
-        const allowedHost = allowedHosts[hostIdx];
-
+      for (const allowedHost of allowedHosts) {
         if (allowedHost === value) {
           return true;
         }