Prevent null value when adding last_xem_refresh via alembic

sickrage/core/databases/main/migrations/versions/014_Add_Last_XEM_Refresh_Column_To_TVShows_Table.py

@@ -26,8 +26,9 @@ def upgrade():
 
  with op.get_context().begin_transaction():
  for row in conn.execute(xem_refresh.select()):
+ last_xem_refresh = row.last_refreshed or datetime.datetime.now().toordinal()
  conn.execute('UPDATE tv_shows SET last_xem_refresh = {} WHERE tv_shows.indexer_id = {}'
- .format(row.last_refreshed, row.indexer_id))
+ .format(last_xem_refresh, row.indexer_id))
 
  op.drop_table('xem_refresh')