message: fix serialize isset crash
diff: @@ -433,8 +433,8 @@ static void* swoole_unserialize_arr(void *buffer, zval *zvalue, uint32_t nNumOfE
  GC_REFCOUNT(ht) = 1;
  GC_TYPE_INFO(ht) = IS_ARRAY;
  - if (ht->nNumUsed)
  - {
  + // if (ht->nNumUsed)
  + //{
  // void *arData = ecalloc(1, len);
  HT_SET_DATA_ADDR(ht, emalloc(HT_SIZE(ht)));
  ht->u.flags |= HASH_FLAG_INITIALIZED;
  @@ -445,7 +445,7 @@ static void* swoole_unserialize_arr(void *buffer, zval *zvalue, uint32_t nNumOfE
  return NULL;
  }
  HT_HASH_RESET(ht);
  - }
  + //}
  int idx;
  