use localized error message

src/app/core/auth/auth.service.ts

@@ -119,7 +119,7 @@ export class AuthService {
         if (hasValue(rd.payload) && rd.payload.authenticated) {
           return rd.payload;
         } else {
-          throw (new Error('Invalid email or password'));
+          throw (new Error('auth.errors.invalid-user'));
         }
       }));