fixup: use btn class for submit input

tubesync/sync/templates/sync/media.html

@@ -32,7 +32,7 @@
       <input name="query" type="text" size=30 placeholder="A key or title containing this text"{% if query %} value="{{ query }}"{% endif %} />
     </div>
     <div class="col m1" style="height: 75px; display: flex; align-items: flex-end;">
-      <input value="Go" style="height: 50px;"type="submit" />
+      <input value="Go" class="btn" style="height: 50px;" type="submit" />
     </div>
   </form>
 </div>