[BUG] fix: Resolved the issue where the delete message method only performs local deletion when the seq is 0.

### OpenIM SDK Version

latest

### OpenIM Server Version

_No response_

### SDK Platform

iOS SDK

### Device Model

test

### Operating System Version

test

### Bug Description and Steps to Reproduce

fix: Resolved the issue where the delete message method only performs local deletion when the seq is 0.

### Screenshots Link

_No response_