Humanize number fix (#6283)

Co-authored-by: Jakub Kuczys <me@jacken.men>

redbot/cogs/cleanup/cleanup.py

@@ -54,6 +54,9 @@ class Cleanup(commands.Cog):
         if ctx.assume_yes:
             return True
 
+        if number > 2**63 - 1:
+            return await ctx.send(_("Try a smaller number instead."))
+
         prompt = await ctx.send(
             _("Are you sure you want to delete {number} messages?").format(
                 number=humanize_number(number)