fix replaceWith calling style deprecation

assets/javascripts/discourse/routes/custom-wizard-index.js.es6

@@ -1,11 +1,14 @@
 import { getCachedWizard } from "../models/custom-wizard";
 import Route from "@ember/routing/route";
+import { inject as service } from '@ember/service';
 
 export default Route.extend({
+  router: service(),
+
   beforeModel() {
     const wizard = getCachedWizard();
     if (wizard && wizard.permitted && !wizard.completed && wizard.start) {
-      this.replaceWith("customWizardStep", wizard.start);
+      this.router.replaceWith("customWizardStep", wizard.start);
     }
   },
 

assets/javascripts/discourse/routes/custom-wizard-step.js.es6

@@ -3,14 +3,17 @@ import { getCachedWizard } from "../models/custom-wizard";
 import Route from "@ember/routing/route";
 import { scrollTop } from "discourse/mixins/scroll-top";
 import { action } from "@ember/object";
+import { inject as service } from '@ember/service';
 
 export default Route.extend({
+  router: service(),
+
   beforeModel() {
     const wizard = getCachedWizard();
     this.set("wizard", wizard);
 
     if (!wizard || !wizard.permitted || wizard.completed) {
-      this.replaceWith("customWizard");
+      this.router.replaceWith("customWizard");
     }
   },