Ignore focus and error on IE7 for disabled select2

For disabled components, focus event was triggered.
On modern browser this error was ignored but not on IE7.

This PR save weird focus event and IE7 JS error.

Author: fdaugan

select2.js

@@ -2583,8 +2583,7 @@ the specific language governing permissions and limitations under the Apache Lic
             this.selection = selection = this.container.find(selector);
 
             var _this = this;
-            this.selection.on("click", ".select2-search-choice:not(.select2-locked)", function (e) {
-                //killEvent(e);
+            this.selection.on("click", ".select2-container:not(.select2-container-disabled) .select2-search-choice:not(.select2-locked)", function (e) {
                 _this.search[0].focus();
                 _this.selectChoice($(this));
             });