adminsettings test: Fix restart detection

We cannot guarantee that the system time on SauceLabs and Github is in
sync. In case the SauceLabs runner's clock is slow the test would have
failed.

Author: webzwo0i

src/tests/frontend/specs/adminsettings.js

@@ -69,15 +69,15 @@ describe('Admin > Settings', function () {
         return null;
       }
     };
+    let oldStartTime;
     await helper.waitForPromise(async () => {
-      const startTime = await getStartTime();
-      return startTime != null && startTime > 0 && Date.now() > startTime;
+      oldStartTime = await getStartTime();
+      return oldStartTime != null && oldStartTime > 0;
     }, 1000, 500);
-    const clickTime = Date.now();
     helper.admin$('#restartEtherpad').click();
     await helper.waitForPromise(async () => {
       const startTime = await getStartTime();
-      return startTime != null && startTime >= clickTime;
+      return startTime != null && startTime > oldStartTime;
     }, 60000, 500);
   });
 });