Update lib/permessage-deflate.js

Co-Authored-By: Luigi Pinca <[email protected]>

Author: yosiat

lib/permessage-deflate.js

@@ -446,7 +446,10 @@ class PerMessageDeflate {
 
       if (fin) data = data.slice(0, data.length - 4);
 
-      // Set callback to null so we won't call it twice if socket is closed
+      //
+      // Ensure that the callback will not be called again in
+      // `PerMessageDeflate#cleanup()`.
+      //
       this._deflate[kCallback] = null;
 
       if (fin && this.params[`${endpoint}_no_context_takeover`]) {