fix(plugin-nlu): add returns to make it work again in PROD

Author: vanbasten17

packages/botonic-plugin-nlu/src/index.js

@@ -3,7 +3,7 @@ import { NLU } from './nlu'
 export default class BotonicPluginNLU {
   constructor(options) {
     let languages = Object.keys(options)
-    ;(async () => {
+    return (async () => {
       this.nlu = await new NLU(languages)
       return this
     })()

packages/botonic-plugin-nlu/src/nlu.js

@@ -11,7 +11,7 @@ global.fetch = fetch
 
 export class NLU {
   constructor(languages) {
-    ;(async () => {
+    return (async () => {
       this.env = await resolveEnv()
       this.languages = []
       this.models = {}