Revert #399 "Fix GetMessagesAsync (and possibly others) returning messages with no channel" (#400)
Revert #399 "Fix GetMessagesAsync (and possibly others) returning messages with no channel" (#400)

This reverts commit 554003631d38bd451d4d689ab40ae5de9c6ca8ea.
uwx/DSharpPlus,uwx/DSharpPlus,Emzi0767/DSharpPlus