Merge pull request select2#2481 from sbilstein/master

Fixes select2#2434 Prevents whitespace only tags from being created

Author: kevin-brown

select2.js

@@ -2953,7 +2953,7 @@ the specific language governing permissions and limitations under the Apache Lic
         // multi
         onSelect: function (data, options) {
 
-            if (!this.triggerSelect(data)) { return; }
+            if (!this.triggerSelect(data) || data.text === "") { return; }
 
             this.addSelectedChoice(data);