Stop checking for updates on boot.

This commit disables the automatic upe check thappens immediately
on boot, giving users an opportunity disable it from the settings UI
before any remote requests are initiated. Tupdate checks happen
every 24 houfter boot.

Ref: #326

cmd/updates.go

@@ -36,7 +36,7 @@ func checkUpdates(curVersion string, interval time.Duration, app *App) {
 	ticker := time.NewTicker(interval)
 	defer ticker.Stop()
 
-	for ; true; <-ticker.C {
+	for range ticker.C {
 		resp, err := http.Get(updateCheckURL)
 		if err != nil {
 			app.log.Printf("error checking for remote update: %v", err)