Bug: NPE in BrowserRunner when no Browser is started


## Quick Description ##
When we perform a test without a browser (no @BrowserAnnotation or @SuppressBrowser) we will get an NullPointerException in the console. This should be fixed.

## Actual Behaviour ##
Running tests without a browser creates a non breaking exception.

## Expected Behaviour ##
Running tests without a browser should run smoothly without any exceptions from the framework.
