[FIX] Get all channels from Slack via REST API (#16767)
[FIX] Get all channels from Slack via REST API (#16767)

Closes #16766
VoiSmart/Rocket.Chat,Sing-Li/Rocket.Chat,subesokun/Rocket.Chat,VoiSmart/Rocket.Chat,subesokun/Rocket.Chat,Sing-Li/Rocket.Chat,VoiSmart/Rocket.Chat,subesokun/Rocket.Chat,subesokun/Rocket.Chat,Sing-Li/Rocket.Chat,Sing-Li/Rocket.Chat