Fix NameError with itertools in client.
Fix NameError with itertools in client.

Harmon758/discord.py,lgkern/PriestPy,mgardne8/discord.py,variablehair/Eggplantato,Theoretical/UselessBot,rapptz/discord.py,imayhaveborkedit/discord.py,Rapptz/discord.py,khazhyk/discord.py,jhgg/discord.py,Harmon758/discord.py