Merge branch '79-handle-unknown-labels-in-label-window' into 'master'

Resolve "handle unknown labels in label window"

Closes #79

See merge request troebs/pycs!73

webui/src/components/projects/project-labels-window.vue

@@ -62,7 +62,9 @@ export default {
 
       for (let image of Object.values(this.currentProject.data)) {
         for (let prediction of Object.values(image['predictionResults'])) {
-          if ('label' in prediction && !result[prediction.label].includes(image)) {
+          if ('label' in prediction
+              && prediction.label in result
+              && !result[prediction.label].includes(image)) {
             result[prediction.label].push(image);
           }
         }