[PATCH proxmox-backup] EncryptionKeysView: Fix API2 error alert messages

[Arthur Bied-Charreton <a.bied-charreton@proxmox.com>]

The errors returned by the encryption-keys and tape-encryption-keys
endpoints are not plain strings, so the alerts displayed on API2 errors
like failed permission checks end up being empty and therefore not very
helpful.

Extract the error messages to display them correctly in alerts.

Signed-off-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>
---
 www/config/EncryptionKeysView.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/www/config/EncryptionKeysView.js b/www/config/EncryptionKeysView.js
index 0f9367c7..bb327814 100644
--- a/www/config/EncryptionKeysView.js
+++ b/www/config/EncryptionKeysView.js
@@ -168,7 +168,7 @@ Ext.define('PBS.config.EncryptionKeysView', {
                     });
                 }
             } catch (error) {
-                Ext.Msg.alert(gettext('Error'), error);
+                Ext.Msg.alert(gettext('Error'), error.result?.message || gettext('Unknown error'));
             }
 
             try {
@@ -181,7 +181,7 @@ Ext.define('PBS.config.EncryptionKeysView', {
                     });
                 }
             } catch (error) {
-                Ext.Msg.alert(gettext('Error'), error);
+                Ext.Msg.alert(gettext('Error'), error.result?.message || gettext('Unknown error'));
             }
 
             let store = view.getStore().rstore;
-- 
2.47.3