[web2py] Exception during file autodelete

[Kurt Grutzmacher]

Using latest web2py trunk.

Upload Field configured for autodelete=True and executing "del
db.t_file_uploads[form.vars.id]" after processing the file:

File "/Users/grutz/src/web2py/gluon/dal.py", line 3696, in __delitem__
    elif not str(key).isdigit() or not self._db(self.id ==
key).delete():
  File "/Users/grutz/src/web2py/gluon/dal.py", line 4381, in delete
    self.delete_uploaded_files()
  File "/Users/grutz/src/web2py/gluon/dal.py", line 4412, in
delete_uploaded_files
    uploadfolder = os.path.join(self.db._folder, '..', 'uploads')
  File "/Users/grutz/src/web2py/gluon/dal.py", line 3329, in
__getattr__
    return dict.__getitem__(self,key)
KeyError: '_folder'

FIX: Line 4412 in dal.py should be:

uploadfolder = os.path.join(self.db._adapter.folder, '..', 'uploads')