Update helpers.py

Traceback (most recent call last):
  File "okcviewer.py", line 18, in <module>
    u.visit(profile.name)
  File "/Users/danielkram/Sites/pyokc/pyokc/pyokc.py", line 318, in visit
    helpers.update_details(profile_tree, prfl.details)
  File "/Users/danielkram/Sites/pyokc/pyokc/helpers.py", line 297, in update_details
    details[title.lower()] = replace_chars(details[title.lower()])
KeyError: 'relationship status'