fix(webstatement): perbaiki logika tombol kirim email

- Menambahkan kondisi tambahan pada tombol "kirim email" agar hanya muncul jika `data.email` tidak kosong.
- Mencegah tombol "kirim email" muncul pada kasus ketika data tersedia tetapi email kosong.

Signed-off-by: Daeng Deni Mardaeni <ddeni05@gmail.com>

resources/views/statements/index.blade.php

@@ -293,7 +293,7 @@
                         }
 
                         // Show send email button if email is not empty and statement is available
-                        if (data.is_available) {
+                        if (data.is_available && data.email) {
                             buttons += `<a class="btn btn-sm btn-icon btn-clear btn-primary" href="statements/${data.id}/send-email" title="Send to Email">
                                 <i class="ki-outline ki-paper-plane"></i>
                             </a>`;