Closes #6306 - Console\RouteNotFoundStrategy invalid index

Solves an issue where the consoles RouteNotFoundStrategy would throw an exception because an arrays index 0 isn't defined.
@Ocramius Looking through the code, getting to this particular method is very, very hard. It's only called by the method `getConsoleUsage()`... which is itself protected, and only invoked by the `handleRouteNotFoundError()` method. Writing a test case that does the entire path would be very, very difficult; this at least tests the root cause.