Remove empty namespace from backo2 typings

types/backo2/backo2-tests.ts

@@ -1,4 +1,4 @@
-import * as Backoff from "backo2";
+import Backoff = require("backo2");
 
 const backoff = new Backoff();
 const backoff2 = new Backoff({});

types/backo2/index.d.ts

@@ -32,6 +32,5 @@ declare class Backoff {
      */
     setJitter(jitter: number): void;
 }
-declare namespace Backoff {}
 
 export = Backoff;