js: cleanup after key import test

--

* one of the public Keys imported was not removed afterwards.

lang/js/BrowserTestExtension/tests/KeyInfos.js

@@ -51,7 +51,9 @@ describe('Key information', function () {
                 const user = result.Keys[0].key.get('userids')[0];
                 expect(user.get('name')).to.equal(
                     inputvalues.publicKeyNonAscii.userid);
-                done();
+                result.Keys[0].delete().then(function (){
+                    done();
+                });
             });
     });
 });