deleteCon = async con_id => {
  try {
    let messages = await db.query(
        'SELECT message, type FROM messages WHERE con_id=?',
        [con_id]
      ),
      deleteMessageFile = promisify(unlink)

    for (let m of messages) {
      if (m.type != 'text') {
        await deleteMessageFile(`${root}/dist/messages/${m.message}`)
      }
    }

    await db.query('DELETE FROM messages WHERE con_id=?', [con_id])
    await db.query('DELETE FROM conversations WHERE con_id=?', [con_id])
  } catch (error) {
    console.log(error)
  }
}
Deletes a conversation
@param {Number} con_id Conversation ID