message: log unexpected errors instead of showing to the users (lib)
diff: @@ -4264,7 +4264,8 @@ error Context::UpdateAutotrackerRule(
  t = user_->related.TaskByID(tid);
  }
  if (tid && !t) {
  - return displayError("task not found");
  + logger.warning("task not found");
  + return noError;
  }
  Project* p = nullptr;
  @@ -4272,14 +4273,16 @@ error Context::UpdateAutotrackerRule(
  p = user_->related.ProjectByID(pid);
  }
  if (pid && !p) {
  - return displayError("project not found");
  + logger.warning("project not found");
  + return noError;
  }
  if (t && t->PID() && !p) {
  p = user_->related.ProjectByID(t->PID());
  }
  if (p && t && p->ID() != t->PID()) {
  - return displayError("task does not belong to project");
  + logger.warning("task does not belong to project");
  + return noError;
  }
  error err = user_->related.UpdateAutotrackerRule(rule_id, terms, tid, pid);
  