Fix comment formatting in AppTest.java

Author: pranavz28

src/test/java/io/percy/examplepercyjavaselenium/AppTest.java

@@ -59,7 +59,7 @@ public void closeBrowser() {
         if (driver != null) {
             driver.quit();
         }
-        // Shutdown our server and make sure the threadpool also terminates.
+        // Shutdown our server and make sure the threadpool also terminates
         server.stop(1);
         serverExecutor.shutdownNow();
     }