UI: allow new keys for VM details (#7793)

diff --git a/ui/src/components/view/DetailSettings.vue b/ui/src/components/view/DetailSettings.vue
index 57c5343..ba96ad6 100644
--- a/ui/src/components/view/DetailSettings.vue
+++ b/ui/src/components/view/DetailSettings.vue
@@ -170,7 +170,11 @@
         return []
       }
       if (!Array.isArray(this.detailOptions[this.newKey])) {
-        return { value: this.detailOptions[this.newKey] }
+        if (this.detailOptions[this.newKey]) {
+          return { value: this.detailOptions[this.newKey] }
+        } else {
+          return ''
+        }
       }
       return this.detailOptions[this.newKey].map(value => {
         return { value: value }