ui: preserve blank lines between verses in customer lyrics view

templates/player.html

@@ -121,6 +121,8 @@
         {% set line = line.strip() %}
         {% if line and not (line.startswith('[') and line.endswith(']')) %}
           <span class="lyric-line">{{ line }}</span>
+        {% elif not line %}
+          <br>
         {% endif %}
       {% endfor %}
     </div>