message: Set memory: None if `statm` call fails on dead pid
diff: @@ -318,8 +318,10 @@ fn list_containers(state: &State) -> Vec<api::Container> {
  {
  const PAGE_SIZE: usize = 4096;
  let pid = f.process().pid();
  - let statm = procinfo::pid::statm(pid as i32).expect("Failed get statm");
  - Some(api::Memory {
  +
  + procinfo::pid::statm(pid as i32)
  + .ok()
  + .map(|statm| api::Memory {
  size: (statm.size * PAGE_SIZE) as u64,
  resident: (statm.resident * PAGE_SIZE) as u64,
  shared: (statm.share * PAGE_SIZE) as u64,
  