$field->options error in field_image.inc

In field_image.inc lines 136 to 141 read:

if (!isset($field->options)) {
    $field['options'][1] = '800x600';
    $field['options'][2] = '512x384';
    $field['options'][3] = '100x100';
    $field['options'][4] = 100;
}

$field is an object, so the assignment does not work and creates a warning. This patch simply replaces those lines with

if (empty($field->options)) {
    $field->options = array(
      1 => '800x600',
      2 => '512x384',
      3 => '100x100',
      4 => 100,
    );
}

Thanks for this great module.
scroogie