http->https for latest version

latest.json

@@ -1,4 +1,4 @@
 {
 	"version": "1.9.1",
-	"url": "http://grafanarel.s3.amazonaws.com/grafana-1.9.1.tar.gz"
+	"url": "https://grafanarel.s3.amazonaws.com/grafana-1.9.1.tar.gz"
 }