OO-1894: reverse the check and allow the command to be null

src/main/java/org/olat/core/gui/components/velocity/VelocityContainer.java

@@ -95,6 +95,7 @@ public class VelocityContainer extends Container {
 	/**
 	 * @see org.olat.core.gui.components.Component#dispatchRequest(org.olat.core.gui.UserRequest)
 	 */
+	@Override
 	protected void doDispatchRequest(UserRequest ureq) {
 		// called when a page-link is clicked ($r.renderCommand)
 		String commandString = ureq.getParameter(COMMAND_ID);

src/main/java/org/olat/course/run/RunMainController.java

@@ -479,7 +479,7 @@ public class RunMainController extends MainLayoutBasicController implements Gene
 				doNodeClick(ureq, tev);
 			}
 		} else if (source == coursemain) {
-			if (event.getCommand().equals("activateCourseNode")) {
+			if ("activateCourseNode".equals(event.getCommand())) {
 				// Events from the JS function o_activateCourseNode() - activate the given node id
 				String nodeid = ureq.getParameter("nodeid");
 				if (nodeid != null) {