Fixes problem when record == ''
Fixes problem when record == ''

Unable to import http://overtag.dk/wordpress/img/suse100/thumbs/snapshot12.png
{'parent': '', 'taxonomy': 'category', 'name': 'Computers', 'slug': 'computers'}
Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
    utility.execute()
  File "site-packages/django/core/management/__init__.py", line 359, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "site-packages/django/core/management/base.py", line 294, in run_from_argv
    self.execute(*args, **cmd_options)
  File "site-packages/django/core/management/base.py", line 345, in execute
    output = self.handle(*args, **options)
  File "wagtail_blog/blog/management/commands/wordpress_to_wagtail.py", line 98, in handle
    self.create_blog_pages(posts, blog_index)
  File "wagtail_blog/blog/management/commands/wordpress_to_wagtail.py", line 372, in create_blog_pages
    self.create_categories_and_tags(new_entry, categories)
  File "wagtail_blog/blog/management/commands/wordpress_to_wagtail.py", line 298, in create_categories_and_tags
    name=record['parent']['name'])[0]

thelabnyc/wagtail_blog,thelabnyc/wagtail_blog