Check_MK Werk 6859: Fixed problem creating custom graphs with many metrics

ID: 6859 Title: Fixed problem creating custom graphs with many metrics Component: metrics Level: 1 Class: Bug fix Version: 1.6.0i1 Since 1.5 creating custom graphs out of graphs with many metrics, e.g. combined graphs, could fail. The custom graph was not created when clicking on "New custom graph..." and nothing visible happened. CMK-1219