don't store empty groupids
don't store empty groupids

gives an exception on oracle and shouldn't be added in the first place
pollopolea/core,owncloud/core,sharidas/core,pollopolea/core,owncloud/core,sharidas/core,sharidas/core,owncloud/core,owncloud/core,phil-davis/core,pollopolea/core,sharidas/core,pollopolea/core,pollopolea/core,owncloud/core,sharidas/core