Merge branch 'type-error-corpus' into 'master'

Prevent a TypeError when loading a navigation page with a type filter

Closes #742

See merge request !1024

vue/Navigation/ElementList.vue

@@ -6,6 +6,7 @@
         placeholder="Filter elements…"
         :filters="availableFilters"
         :disabled="loading"
+        v-if="corpus.id"
         v-model="selectedFilters"
         v-on:submit="submitFilters"
       />