Added case for correct group identifier
Added case for correct group identifier

Addresses review comment
https://github.com/ebu/ebu-tt-live-toolkit/pull/406#discussion_r11139503
9

bbc/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit,bbc/ebu-tt-live-toolkit,bbc/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit