ftr/PartsInGoToMenu: fix handling if parts have no id

if parts had no id, the parts menu would have been shown but not clickable because the parts could ne be referenced.
this prevents breaking for some sources.

app/view/window/source/SourceView.js

@@ -255,7 +255,8 @@ Ext.define('EdiromOnline.view.window.source.SourceView', {
 
         // iterate over submitted movements and push them to movementItems variable
         movements.data.each(function(movement) {
-            if(movement.data.parts.length === 0) {
+            // check if parts exist and if they have ids
+            if(movement.data.parts.length === 0 || movement.data.parts[0].id === null || movement.data.parts[0].id === "") {
                 movementItems.push({
                     text: movement.get('name'),
                     handler: Ext.bind(me.gotoMovement, me, movement.get('id'), true)