🗑️ Remove deprecated code (#1225)

src/components/Dashboard/Modals/EditAppModal/EditAppModal.tsx

@@ -71,7 +71,7 @@ export const EditAppModal = ({
       behaviour: {
         externalUrl: (url: string) => {
           if (url === undefined || url.length < 1) {
-            return null;
+            return 'External URI is required';
           }
 
           if (!url.match(appUrlWithAnyProtocolRegex)) {

src/components/Dashboard/Modals/SelectElement/Components/Overview/AvailableElementsOverview.tsx

@@ -101,7 +101,7 @@ export const AvailableElementTypes = ({
                   },
                   behaviour: {
                     isOpeningNewTab: true,
-                    externalUrl: '',
+                    externalUrl: 'https://homarr.dev',
                   },
 
                   area: {