Line 715 should be.

  //checking if project is part of a group
  elseif (isset($project->og_groups) 
    && is_array($project->og_groups) 
    && $project->type !== 'group'
  ) {
    foreach ($project->og_groups as $group) {
      $querystring[] = $group;
    }
  }
 
  return (0 < count($querystring))
      ? 'gids[]='. implode(',', $querystring)
      : NULL;

I am sorry, but I havent figured out how to add patches yet :)