message: only show spawn day shouts button with shouts enabled
diff: <p v-translate="{ years: spawnDayYear }">
  That means on this day, they have been on Game Jolt for %{ years }!
  </p>
  + <template v-if="user.shouts_enabled">
  <p>
  <translate>
  It is customary to wish them a happy Spawn Day, so you should too.
  <translate>Send your wishes</translate>
  </app-button>
  </template>
  + </template>
  </app-alert-dismissable>
  </template>
  