Description of problem: When adding new "Servlet Container" in Undertow, and then loading it's configurations, it fails with error "No configuration was retrieved. This means that either the plugin failed to load the configuration or that configuration collection is merely switched off in the connection settings." The problem is that "Servet Container" is created without creating it's settings, which are "jsp" and "websocket". So alongside creating new Servlet Container on Undertow side, it needs to be created it's settings as well, like: "/subsystem=undertow/servlet-container=testcontainer/setting=jsp:add(...)" :/subsystem=undertow/servlet-container=testcontainer/setting=websockets:add(...)"
Creates the settings (jsp and websockets) upon "Servlet Container" creation. This also fixes error introduced in the commit of Bug 1313955. commit da07b04076014e80f3f1befb694da0bf98165f3b Author: Josejulio Mart\u00ednez <jmartine> Date: Thu Mar 31 13:25:49 2016 -0600 Bug 1321941 - EAP7 - Undertow - new created Servlet Container not loaded Creates JSP and Websockets settings nodes when trying to create Servlet Container. Fixes XML error (changed readonly for readOnly)
Verified on revision jon33-eap-update04 ER01