[improve] HeaderSettings ignores columns without label or title

Author: Ken Berkeley

dist/min.js

@@ -12,5 +12,5 @@
 
 <script src="//unpkg.com/jquery@2.1.4/dist/jquery.min.js"></script>
 <script src="//unpkg.com/bootstrap@3.3.5/dist/js/bootstrap.min.js"></script>
-<script type="text/javascript" src="client.c09d43eb.js"></script></body>
+<script type="text/javascript" src="client.1e46594b.js"></script></body>
 </html>

examples/dist/client.c09d43eb.js examples/dist/client.1e46594b.jsexamples/dist/client.c09d43eb.js renamed to examples/dist/client.1e46594b.js

@@ -1,7 +1,7 @@
 {
   "name": "vue2-datatable-component",
   "description": "The best Datatable for Vue.js 2.x which never sucks",
-  "version": "2.1.16",
+  "version": "2.1.17",
   "main": "dist/min.js",
   "module": "src/main.js",
   "author": "Ken Berkeley <kenberkeley@foxmail.com>",

examples/dist/index.html

@@ -91,7 +91,10 @@ export default {
   },
   computed: {
     colGroups () {
-      return groupBy(this.columns, 'group')
+      return groupBy(
+        this.columns.filter(col => col.label || col.title),
+        'group'
+      )
     },
     drpMenuStyle () {
       const w = Object.keys(this.colGroups).length * 150