[FIXED JENKINS-34880] do not show warnings if tool installer is present in at...

[FIXED JENKINS-34880] do not show warnings if tool installer is present in at least 1 update site (#2361)

core/src/main/java/hudson/model/DownloadService.java

@@ -403,7 +403,7 @@ public class DownloadService extends PageDecorator {
                     jsonString = loadJSONHTML(new URL(site + ".html?id=" + URLEncoder.encode(getId(), "UTF-8") + "&version=" + URLEncoder.encode(Jenkins.VERSION, "UTF-8")));
                     toolInstallerMetadataExists = true;
                 } catch (Exception e) {
-                    LOGGER.log(Level.WARNING, "Could not load json from " + site, e );
+                    LOGGER.log(Level.FINE, "Could not load json from " + site, e );
                     continue;
                 }
                 JSONObject o = JSONObject.fromObject(jsonString);