title: I can't get certain guild with discord.py
body: <p>I'm trying to take certain roles when bot starting. First i need to take guild but i couldn't achieve it.</p>
  <pre><code>takenGuild = client.get_guild(myServerID)
  </code></pre>
  <p>takenGuild returning None</p>
  <p>When i try to loop guilds</p>
  <pre><code>for guild in client.guilds:
      print(guild.id)
  </code></pre>
  <p>it's not printing anything.</p>
  <p>My whole code :</p>
  <pre><code>import discord
  from discord.ext import commands, tasks
  from discord.utils import get
  
  client = commands.Bot(command_prefix = '.')
  
  
  takenGuild = client.get_guild(123123123123123123)
  print(takenGuild.id)
  
  for guild in client.guilds:
      print(guild)
      print(guild.id)
      
      
  client.run('Token')
  </code></pre>