imagemodule + localization: reset to defaults causes problems

There is an bug in the imagemodule when used together with localization.

When the other language is active en you want to reset to defaults in de imagemodule setting
the required "thumbnail" and "preview" in the image sizes table get translated en become editable.
New images also get the translated filename in the database previous entries still have the old filename.
This results in the "loss" of the thumbs of the old images.

The problem can be fixed by removing the call to the t() function in _image_get_sizes();

Current code:

function _image_get_sizes() {
  return variable_get('image_sizes', array(array('width' => 100, 'height' => 100, 'label' => t('thumbnail')),
                                           array('width' => 640, 'height' => 640, 'label' => t('preview'))));
}

My fix:

function _image_get_sizes() {
  return variable_get('image_sizes', array(array('width' => 100, 'height' => 100, 'label' => 'thumbnail'),
                                           array('width' => 640, 'height' => 640, 'label' => 'preview')));
}