add App.License, remove utils.IsLicensed / utils.License calls (#8203)

app/webhook.go

@@ -632,7 +632,7 @@ func (a *App) HandleIncomingWebhook(hookId string, req *model.IncomingWebhookReq
 		}
 	}
 
-	if utils.IsLicensed() && *a.Config().TeamSettings.ExperimentalTownSquareIsReadOnly &&
+	if a.License() != nil && *a.Config().TeamSettings.ExperimentalTownSquareIsReadOnly &&
 		channel.Name == model.DEFAULT_CHANNEL {
 		return model.NewAppError("HandleIncomingWebhook", "api.post.create_post.town_square_read_only", nil, "", http.StatusForbidden)
 	}