[Enhance]Master processing admin/getIp commands should be modified to not load persistent data

[true1064]

When master handling HTTP API “admin/getIp", it calls loadClusterValue(), which loads the persisted metadata and stores it to memory. For the admin/getIp API: (1) It is not necessary to read persistent data. Directly return the value in memory is ok, which can reduce the performance overhead; (2) This should be a read-only interface and should not trigger changes to values in memory;

[leonrayang]

1