Check_MK Werk 0281: statgrab_net.ctr: only inventorize interfaces with actual traffic

ID: 0281 Title: statgrab_net.ctr: only inventorize interfaces with actual traffic Component: Checks & Agents Level: 1 Class: Bug Fix Version: 1.2.5i1 Some virtual interfaces with no counter information got inventorized - doesn't made sense. Now we only inventorize interfaces which also provide traffic information.