message: Fix cant full sync bug
diff: @@ -131,6 +131,14 @@ void PikaReplServerConn::HandleTrySyncRequest(void* arg) {
  << ", pro_offset_: " << slave_boffset.offset();
  pre_success = false;
  }
  + if (pre_success) {
  + std::string confile = NewFileName(partition->logger()->filename, slave_boffset.filenum());
  + if (!slash::FileExists(confile)) {
  + LOG(INFO) << "Partition: " << partition_name << " binlog has been purged, may need full sync";
  + try_sync_response->set_reply_code(InnerMessage::InnerResponse::TrySync::kSyncPointBePurged);
  + pre_success = false;
  + }
  + }
  if (pre_success) {
  PikaBinlogReader reader;
  reader.Seek(partition->logger(), slave_boffset.filenum(), slave_boffset.offset());
  @@ -147,15 +155,6 @@ void PikaReplServerConn::HandleTrySyncRequest(void* arg) {
  }
  }
  - if (pre_success) {
  - std::string confile = NewFileName(partition->logger()->filename, slave_boffset.filenum());
  - if (!slash::FileExists(confile)) {
  - LOG(INFO) << "Partition: " << partition_name << " binlog has been purged, may need full sync";
  - try_sync_response->set_reply_code(InnerMessage::InnerResponse::TrySync::kSyncPointBePurged);
  - pre_success = false;
  - }
  - }
  -
  if (pre_success) {
  if (!g_pika_rm->CheckPartitionSlaveExist(RmNode(node.ip(), node.port(), table_name, partition_id))) {
  int32_t session_id = g_pika_rm->GenPartitionSessionId(table_name, partition_id);
  