message: Fixed bug causing header on modal to not appear.
diff: <div class="modal-content">
  <div class='card'>
  <header class="card-header" :id='id'>
  - <p class='card-header-title' v-if="selectedMod !== null">Select a version of {{selectedMod.getName()}} to download</p>
  + <p class='card-header-title' v-if="selectedThunderstoreMod !== null">Select a version of {{selectedThunderstoreMod.getName()}} to download</p>
  </header>
  <div class='card-content'>
  <p>It's recommended to select the latest version of all mods.</p>
  