friends file can get corrupted

[sascha_silbe]

After adding a client without a public key as a friend, the friends file is corrupted:

1266938905.479586 ERROR root: Error parsing friends file
Traceback (most recent call last):
  File "/home/sascha.silbe/sugar-jhbuild/install/lib/python2.5/site-packages/jarabe/model/friends.py", line 67, in load
    success = cp.read([self._path])
  File "/usr/lib/python2.5/ConfigParser.py", line 267, in read
    self._read(fp, filename)
  File "/usr/lib/python2.5/ConfigParser.py", line 490, in _read
    raise e
ParsingError: File contains parsing errors: /home/sascha.silbe/.sugar/default/friends
        [line  5]: '[]\n'

[sascha_silbe]

The whole presence stuff will be rewritten from scratch for 0.90, so doesn't matter anymore.