Add check for 401 errors in interceptor

src/app/authentication.interceptor.ts

@@ -8,8 +8,6 @@ import { Observable } from 'rxjs/Observable';
 
 const AUTH_HEADER_KEY = 'Arsnova-Auth-Token';
 
-const AUTH_HEADER_KEY = 'Arsnova-Auth-Token';
-
 @Injectable()
 export class AuthenticationInterceptor implements HttpInterceptor {