Fix default null/empty value

disarticulate · web-flow · commit 670850614517 · 2018-10-20T13:45:28.000-05:00
removeLayer attempts to filter:
```
this.layersToAdd = this.layersToAdd.filter((l) =&gt; l.name !== layer.name);
```
Null value creates undefined error.
diff --git a/src/components/LMap.vue b/src/components/LMap.vue
@@ -109,7 +109,7 @@ export default {
       for (var layer in this.layersToAdd) {
         this.layerControl.addLayer(layer);
       }
-      this.layersToAdd = null;
+      this.layersToAdd = [];
     },
     addLayer (layer, alreadyAdded) {
       if (layer.layerType !== undefined) {

Original file line number	Diff line number	Diff line change
`@@ -109,7 +109,7 @@ export default {`
`109`	`109`	`for (var layer in this.layersToAdd) {`
`110`	`110`	`this.layerControl.addLayer(layer);`
`111`	`111`	`}`
`112`		`- this.layersToAdd = null;`
	`112`	`+ this.layersToAdd = [];`
`113`	`113`	`},`
`114`	`114`	`addLayer (layer, alreadyAdded) {`
`115`	`115`	`if (layer.layerType !== undefined) {`