added locale backup + en support

src/app/services/i18n.service.ts

@@ -1,18 +1,18 @@
 import {Injectable} from '@angular/core';
 import {HttpClient} from '@angular/common/http';
-import { environment } from '../../environments/environment';
+import {environment} from '../../environments/environment';
 
 @Injectable({
     providedIn: 'root',
 })
 export class I18nService {
 
-    locale: string;
-    locales : any = ["de-informal"]; 
+    locale: string = "de-informal";
+    locales: any = ["de-informal"];
     i18n: any;
 
     constructor(private http: HttpClient) {
-        
+
     }
 
     getLocales() {
@@ -28,29 +28,36 @@ export class I18nService {
     }
 
     async fetch() {
-        
+
         let browserLocale = navigator.language;
 
         if(browserLocale.indexOf("-") != -1) {
             browserLocale = browserLocale.split("-")[0];
         }
 
-        let locale =  localStorage.getItem("bstly.locale") || browserLocale || this.locales[0];
+        let locale = localStorage.getItem("bstly.locale") || browserLocale || this.locales[0];
 
         if(locale == 'de') {
             locale = 'de-informal';
         }
 
-        this.locales = await this.http.get(environment.apiUrl + "/i18n").toPromise();
+        try {
+            this.locales = await this.http.get(environment.apiUrl + "/i18n").toPromise();
+        } catch(e) {
+            console.debug("fallback to default locales");
+        }
 
         if(this.locales.indexOf(locale) == -1) {
             locale = this.locales[0];
         }
 
         this.setLocale(locale);
-
-        this.i18n = await this.http.get(environment.apiUrl + "/i18n/" + locale).toPromise();
-
+        try {
+            this.i18n = await this.http.get(environment.apiUrl + "/i18n/" + locale).toPromise();
+        } catch(e) {
+            this.i18n = await this.http.get("/assets/i18n/" + locale + ".json").toPromise();
+            console.debug("fallback to default locale");
+        }
     }
 
     get(key, args: string[]): string {