Remove broken upgrade wizard (#5283)

core/src/main/java/hudson/PluginManager.java

@@ -788,8 +788,6 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
 
             LOGGER.log(INFO, "Upgraded Jenkins from version {0} to version {1}. Loaded detached plugins (and dependencies): {2}",
                     new Object[] {lastExecVersion, Jenkins.VERSION, loadedDetached});
-
-            InstallUtil.saveLastExecVersion();
         } else {
             final Set<DetachedPluginsUtil.DetachedPlugin> forceUpgrade = new HashSet<>();
             // TODO using getDetachedPlugins here seems wrong; should be forcing an upgrade when the installed version is older than that in WEB-INF/detached-plugins/