sentinel dashboard can only query the last minute

## Issue Description
My service has five minutes of metric data, but when there is no data in the last minute, the first four minutes of metric data cannot be queried.
Type: *bug report*

### Describe what happened (or what feature you want)

### Describe what you expected to happen
When I need to query the data of the last 5 minutes, I can query the data of the last 5 minutes

### How to reproduce it (as minimally and precisely as possible)
My service has five minutes of metric data, this is screenshot.

when there is no data in the last minute, the first four minutes of metric data cannot be queried.
when new metric was added in recently 1 min, the result was correct

### Tell us your environment
sentinel dashboard version: 1.8.4-SNAPSHOT, that's newest version from master

### Anything else we need to know?
@sczyh30 Hello Eric Zhao，I would like to know if it is so designed

Start by reproducing the issue in the Sentinel dashboard version 1.8.4-SNAPSHOT with five minutes of metric data and no data in the latest minute, comparing it with the case where a new metric arrives. Done means the dashboard can query all five minutes of existing data even when the most recent minute is empty.

Written by the indexing model from the issue text.