Appease the linter

Author: sandhose

frontend/tests/routes/account/index.test.tsx

@@ -21,7 +21,7 @@ describe("Account home page", () => {
   describe("display name edit box", () => {
     it("lets edit the display name", async () => {
       // TODO: a better way to wait on delays
-      let advance: () => void;
+      let advance: () => void = () => {};
       const wait = new Promise((resolve) => {
         advance = () => resolve(void 0);
       });

frontend/tests/routes/reset-cross-signing.test.tsx

@@ -34,7 +34,7 @@ describe("Reset cross signing", () => {
 
   it("calls the callback on success", async () => {
     // TODO: a better way to wait on delays
-    let advance: () => void;
+    let advance: () => void = () => {};
     const wait = new Promise((resolve) => {
       advance = () => resolve(void 0);
     });