message: follow_me: fix double sending of location
  We changed the behavior of add_call_every a while ago. It now triggeres
  immedately as well as later. This means that the manual immediate
  trigger is no longer necessary. Otherwise, this leads to weird double
  bursts.
diff: @@ -156,15 +156,12 @@ FollowMe::Result FollowMeImpl::set_target_location(const FollowMe::TargetLocatio
  if (_target_location_cookie) {
  _parent->reset_call_every(_target_location_cookie);
  } else {
  - // Register now for sending in the next cycle.
  + // Register to send it immediately as well as in the next cycle.
  _parent->add_call_every(
  [this]() { send_target_location(); }, SENDER_RATE, &_target_location_cookie);
  }
  }
  - // Send it immediately for now.
  - send_target_location();
  -
  return FollowMe::Result::Success;
  }
  