Merge 3.6.2 into master (#5211)

* Add webhook cache

* Add channel by name cache

* Fxing profiles in channels cache

* Fix merge

api/command_msg.go

@@ -64,7 +64,7 @@ func (me *msgProvider) DoCommand(c *Context, args *model.CommandArgs, message st
 	channelName := model.GetDMNameFromIds(c.Session.UserId, userProfile.Id)
 
 	targetChannelId := ""
-	if channel := <-app.Srv.Store.Channel().GetByName(c.TeamId, channelName); channel.Err != nil {
+	if channel := <-app.Srv.Store.Channel().GetByName(c.TeamId, channelName, true); channel.Err != nil {
 		if channel.Err.Id == "store.sql_channel.get_by_name.missing.app_error" {
 			if directChannel, err := app.CreateDirectChannel(c.Session.UserId, userProfile.Id); err != nil {
 				c.Err = err