Unignores all channels in this server from being processed.

        To use this command you must have the Manage Channels permission or have the
        Bot Admin role.

async def unignore_all(self, ctx):
        """Unignores all channels in this server from being processed.

        To use this command you must have the Manage Channels permission or have the
        Bot Admin role.
        """
        channels = [c for c in ctx.message.server.channels if c.type is discord.ChannelType.text]
        await ctx.invoke(self.unignore, *channels)