[gh-1] Fix Unl.hasParentNodeWithClass for plain text nodes

plugins/unl/editor_plugin.js

@@ -5,7 +5,7 @@
 var Unl = {};
 
 Unl.hasParentNodeWithClass = function(childNode, parentClass) {
-	for (var selectedNode = childNode; selectedNode.id != 'maincontent'; selectedNode = selectedNode.parentNode) {
+	for (var selectedNode = childNode; selectedNode.id != 'maincontent' && !selectedNode.body; selectedNode = selectedNode.parentNode) {
 		if (typeof selectedNode.className !== 'undefined' && selectedNode.className.search(parentClass) >= 0) {
 			return selectedNode;
 		}