Fix loading hang

Import and add loading property to pages that are disabling
forms based on LoadingBarMixin loading property.

Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
Change-Id: I1669bff2572422327566a3afe023633eb0b729f4
diff --git a/src/env/components/FirmwareSingleImage/FirmwareSingleImage.vue b/src/env/components/FirmwareSingleImage/FirmwareSingleImage.vue
index 92c4e80..426d5c2 100644
--- a/src/env/components/FirmwareSingleImage/FirmwareSingleImage.vue
+++ b/src/env/components/FirmwareSingleImage/FirmwareSingleImage.vue
@@ -216,7 +216,7 @@
 import ModalRebootBackup from './FirmwareSingleImageModalRebootBackup';
 
 import VuelidateMixin from '@/components/Mixins/VuelidateMixin.js';
-import LoadingBarMixin from '@/components/Mixins/LoadingBarMixin';
+import LoadingBarMixin, { loading } from '@/components/Mixins/LoadingBarMixin';
 import BVToastMixin from '@/components/Mixins/BVToastMixin';
 
 export default {
@@ -241,6 +241,7 @@
       tftpIpAddress: null,
       tftpFileName: null,
       timeoutId: null,
+      loading,
     };
   },
   computed: {