删除消息

[[OIMManager manager] deleteMessage:conversationID
                        clientMsgID:clientMsgID
                          onSuccess:^(NSString * _Nullable data) {
    // 本端删除成功，从本地界面移除该消息
    [self removeMessageFromUI:clientMsgID];
}
                          onFailure:^(NSInteger code, NSString * _Nullable msg) {
    // 处理删除失败
}];