Better types for WebAPI

ts/textsecure/Utils.ts

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import * as log from '../logging/log';
+import { HTTPError } from './Errors';
 
 export async function handleStatusCode(status: number): Promise<void> {
   if (status === 499) {
@@ -11,7 +12,7 @@ export async function handleStatusCode(status: number): Promise<void> {
   }
 }
 
-export function translateError(error: Error): Error | undefined {
+export function translateError(error: HTTPError): HTTPError | undefined {
   const { code } = error;
   if (code === 200) {
     // Happens sometimes when we get no response. Might be nice to get 204 instead.