Fix ajax-field 'quietMillis' to 'delay'.

See select2 documentation at https://select2.github.io/options.html#ajax

select2/select2-tests.ts

@@ -99,7 +99,7 @@ $("#e7").select2({
     ajax: {
         url: "http://api.rottentomatoes.com/api/public/v1.0/movies.json",
         dataType: 'jsonp',
-        quietMillis: 100,
+        delay: 100,
         data: function (term, page) {
             return {
                 q: term,

select2/select2.d.ts

@@ -25,7 +25,7 @@ interface Select2AjaxOptions {
     */
     url?: any;
     dataType?: string;
-    quietMillis?: number;
+    delay?: number;
     cache?: boolean;
     data?: (term: string, page: number, context: any) => any;
     results?: (term: any, page: number, context: any) => any;