Fixes emmetio#491 No expand when css abbr ends with : (emmetio#492)

Thank! Please note that this is an obsolete version of Emmet, I’m working on a new version now: https://www.npmjs.com/~emmetio

PS: still no response from VSCode devs regarding my last email about MS support for new Emmet 😔

lib/resolver/css.js

@@ -829,7 +829,7 @@ define(function(require, exports, module) {
 			}
 
 			if (!snippet) {
-				if (!abbrData.property) {
+				if (!abbrData.property || abbrData.property.endsWith(':')) {
 					return null;
 				}
 				snippet = abbrData.property + ':' + defaultValue;