Upgrade/Install: Do not remove event handlers when trying to update a theme.

Previously, when clicking "Update now" the callbacks were erroneously removed. This prevented opening the filesystem credentials modal for a second time.

Fixes #37285.

git-svn-id: https://develop.svn.wordpress.org/trunk@38019 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/js/theme.js

@@ -611,7 +611,6 @@ themes.view.Theme = wp.Backbone.View.extend({
 	updateTheme: function( event ) {
 		var _this = this;
 		event.preventDefault();
-		this.$el.off( 'click', '.update-message' );
 
 		wp.updates.maybeRequestFilesystemCredentials( event );