JS error if CSS excluder not defined

Swear I'm not trying to overload the queue! Just trying to help!

On a Drupal 6.14 install I was getting a broken function call when I didn't define a "Non Editable Images (CSS Class)" (wasn't a problem on a fresher 6.16 pressflow site.)

This is how I've worked around it:

//Prevent a lack of a skip code from erroring out the JS
picnik_css_skip_not = '';

if (Drupal.settings.picnik_css_skip) {
  picnik_css_skip_not = ':not('+Drupal.settings.picnik_css_skip+')';
}

I then mended the following JS accordingly.