fix submit button disabled breaking async task

res/css/views/dialogs/keybackup/_CreateKeyBackupDialog.scss

@@ -85,3 +85,9 @@ limitations under the License.
     flex: 1;
     white-space: nowrap;
 }
+
+.mx_CreateKeyBackupDialog {
+    details .mx_AccessibleButton {
+        margin: 1em 0; // emulate paragraph spacing because we can't put this button in a paragraph due to HTML rules
+    }
+}