Limit Upload File Types in WP Editor but not affect Admin Dashboard

I'm using the WP Editor on a page outside of the admin section when allowing my users to create a post. I'm enabling it like this:

$editor_id = 'post_information';
wp_editor( $content, $editor_id );

I'm trying to limit the users to only be able to upload a .jpg, .png, .gif file and have the following code to do this:

add_filter('wp_handle_upload_prefilter', 'yoursite_wp_handle_upload_prefilter');
function yoursite_wp_handle_upload_prefilter($file) {
  // This bit is for the flash uploader
  if ($file['type']=='application/octet-stream' && isset($file['tmp_name'])) {
    $file_size = getimagesize($file['tmp_name']);
    if (isset($file_size['error']) && $file_size['error']!=0) {
      $file['error'] = "Unexpected Error: {$file_size['error']}";
      return $file;
    } else {
      $file['type'] = $file_size['mime'];
    }
  }

  list($category,$type) = explode('/',$file['type']);

  if('image'!=$category || !in_array($type,array('jpg','jpeg','gif','png'))) {
    $file['error'] = "Sorry, you can only upload a .GIF, a .JPG, or a .PNG image file.";
  }

  return $file;
}

This works fine and will only allow my users to upload those file types. However, if I try and upload a plugin in a zip file or something within the dashboard section it hits this code and won't let me upload it. Is there a way to limit this for the WP Editor but not have it affect any of the admin dashboard uploads?