fix sonar issue

lib/generator.js

@@ -98,7 +98,7 @@ class Generator {
     const options = arguments[arguments.length - 1];
     const invalidOptions = getInvalidOptions(GENERATOR_OPTIONS, options || []);
     if (invalidOptions.length) throw new Error(`These options are not supported by the generator: ${invalidOptions.join(', ')}`);
-    if (options && options.registry) {
+    if (options && this.verifyRegistryOption(options.registry)) {
       const invalidRegOptions = getInvalidOptions(REGISTRY_OPTIONS, options.registry || []);
       this.isInvalidRegOptions(invalidRegOptions);
     }
@@ -161,6 +161,18 @@ class Generator {
   isInvalidRegOptions(invalidRegOptions) {
     if (invalidRegOptions.length) throw new Error(`These options are not supported by the generator to configure private registry: ${invalidRegOptions.join(', ')}`);
   }
+
+  /**
+    * Check if the Registry Options is present or not.
+    * 
+    * @private
+    * @param {Object} registryOption Registry Options.
+    * @return {boolean}
+    */
+
+  verifyRegistryOption(registryOption) {
+    return registryOption === null;
+  }
 
   /**
    * Generates files from a given template and an AsyncAPIDocument object.