message: Manager shouldn't replace user's mode configuration
  fix
diff: @@ -456,6 +456,7 @@ impl ManagerService {
  config.local_addr = self.context.config().local_addr.clone();
  + // Mode
  if let Some(mode) = p.mode {
  config.mode = match mode.parse::<Mode>() {
  Ok(m) => m,
  @@ -464,6 +465,8 @@ impl ManagerService {
  return Err(err);
  }
  };
  + } else {
  + config.mode = self.context.config().mode;
  }
  // TCP_NODELAY
  @@ -477,9 +480,6 @@ impl ManagerService {
  config.udp_timeout = self.context.config().udp_timeout;
  config.udp_max_associations = self.context.config().udp_max_associations;
  - // Mode
  - config.mode = self.context.config().mode;
  -
  // ACL
  // FIXME: AccessControl structure may be quite expensive to copy
  config.acl = self.context.config().acl.clone();
  