[oslo] New courtesy ping list for Ussuri

As we discussed at the beginning of the cycle, I'll be clearing the current ping list in the next few weeks. This is to prevent courtesy pinging people who are no longer active on the project. If you wish to continue receiving courtesy pings at the start of the Oslo meeting please add yourself to the new list on the agenda template [0]. Note that the new list is above the template, called "Courtesy ping list for Ussuri". If you add yourself again to the end of the existing list I'll assume you want to be left on though. :-) Thanks. -Ben 0: https://wiki.openstack.org/wiki/Meetings/Oslo#Agenda_Template