new_contents: import sqlite3
  import os
  
  
  def do_migration(conf):
      db_path = os.path.join(conf.data_dir, "lbrynet.sqlite")
      connection = sqlite3.connect(db_path)
      cursor = connection.cursor()
  
      query = "select stream_hash, sd_hash from main.stream"
      for stream_hash, sd_hash in cursor.execute(query):
          head_blob_hash = cursor.execute(
              "select blob_hash from stream_blob where position = 0 and stream_hash = ?",
              (stream_hash,)
          ).fetchone()
          if not head_blob_hash:
              continue
          cursor.execute("update blob set should_announce=1 where blob_hash in (?, ?)", (sd_hash, head_blob_hash[0],))
      connection.commit()
      connection.close()
  
subject: add migrator for previous bugs