Make the group model return maintainer level when it is not set
Make the group model return maintainer level when it is not set

mmkassem/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq