fix(store): fix type error after pinia version upgrade

vben

2021-06-19 e8d6f8851efd7076946486864936f1797280d3ba

 src/store/modules/lock.ts

@@ -16,7 +16,7 @@
    lockInfo: Persistent.getLocal(LOCK_INFO_KEY),
  }),
  getters: {
    getLockInfo() {
    getLockInfo(): Nullable<LockInfo> {
      return this.lockInfo;
    },
  },