Revert "Adding caching to get channel member (#5518)"

This reverts commit ba028ed74b.

app/web_hub.go

@@ -173,18 +173,6 @@ func InvalidateCacheForUser(userId string) {
 	}
 }
 
-func InvalidateCacheForChannelMember(channelId string, userId string) {
-	InvalidateCacheForChannelMemberSkipClusterSend(channelId, userId)
-
-	if einterfaces.GetClusterInterface() != nil {
-		einterfaces.GetClusterInterface().InvalidateCacheForChannelMember(channelId, userId)
-	}
-}
-
-func InvalidateCacheForChannelMemberSkipClusterSend(channelId string, userId string) {
-	Srv.Store.Channel().InvalidateMember(channelId, userId)
-}
-
 func InvalidateCacheForUserSkipClusterSend(userId string) {
 	Srv.Store.Channel().InvalidateAllChannelMembersForUser(userId)
 	Srv.Store.User().InvalidateProfilesInChannelCacheByUser(userId)