CardBadges: Count checkboxes started with "+ [ ]" 
CardBadges: Count checkboxes started with "+ [ ]" 

Fixes #2187

Signed-off-by: Johannes Reiff <1d6e1cf70ec6f9ab28d3ea4b27a49a77654d370e@jreiff.de>
juliushaertl/deck,nextcloud/deck,juliushaertl/deck,nextcloud/deck,juliushaertl/deck,nextcloud/deck