Display age on profile if a year has been entered.

src/Users/profile.php

@@ -206,6 +206,7 @@ function user_profile_get(int $userId): array {
                     u.`user_about_parser`, u.`user_about_content`,
                     u.`user_signature_parser`, u.`user_signature_content`,
                     %1$s,
+                    TIMESTAMPDIFF(YEAR, IF(u.`user_birthdate` < \'0001-01-01\', NULL, u.`user_birthdate`), NOW()) AS `user_age`,
                     COALESCE(u.`user_title`, r.`role_title`) AS `user_title`,
                     COALESCE(u.`user_colour`, r.`role_colour`) AS `user_colour`,
                     `user_background_settings` & 0x0F AS `user_background_attachment`,

templates/profile/_layout/header.twig

@@ -42,7 +42,7 @@
                 <div class="profile__header__country">
                     <div class="flag flag--{{ profile.user_country|lower }}"></div>
                     <div class="profile__header__country__name">
-                        {{ profile.user_country|country_name }}
+                        {{ profile.user_country|country_name }}{% if profile.user_age > 0 %}, {{ profile.user_age }} year{{ profile.user_age != 's' ? 's' : '' }} old{% endif %}
                     </div>
                 </div>
             {% else %}