Made msiEndpoint and msiSecret optional

runtime/ms-rest-azure/index.d.ts

@@ -940,13 +940,13 @@ export interface MSIAppServiceOptions extends MSIOptions {
    * Either provide this parameter or set the environment varaible `MSI_ENDPOINT`.
    * For example: `export MSI_ENDPOINT="http://127.0.0.1:41741/MSI/token/"`
    */
-  msiEndpoint: string;
+  msiEndpoint?: string;
   /**
    * @property {string} [msiSecret] - The secret used in communication between your code and the local MSI agent.
    * Either provide this parameter or set the environment varaible `MSI_SECRET`.
    * For example: `export MSI_SECRET="69418689F1E342DD946CB82994CDA3CB"`
    */
-  msiSecret: string;
+  msiSecret?: string;
   /**
    * @property {string} [msiApiVersion] - The api-version of the local MSI agent. Default value is "2017-09-01".
    */