This should finally fix the problem, that the first time the completion popup...

This should finally fix the problem, that the first time the completion popup is shown, the first group is empty.
The problem was that group titles did not get created, while m_hasGroup was empty, if a model later on in the chain caused  m_hasGroup to be set, the first models didn't have valid groups -> no header text displayed. This definitely needs testing and should not be backported yet, as long as it is not being tested

CCBUG: 315189