Code review comment for lp:~suutari-olli/openlp/click-slide-to-go-live-from-blank

Traceback (most recent call last):
  File "/home/tim/Projects/OpenLP/openlp/click-slide-to-go-live-from-blank/openlp/core/ui/slidecontroller.py", line 1401, in on_preview_double_click
    elif not Registry().get_flag('has doubleclick added item to service') is True:
  File "/home/tim/Projects/OpenLP/openlp/click-slide-to-go-live-from-blank/openlp/core/common/registry.py", line 160, in get_flag
    raise KeyError('Working Flag {key} not found in list'.format(key=key))
KeyError: 'Working Flag has doubleclick added item to service not found in list'

Blank live and double click on a preview slide.