Hide playlist widget when user has no playlists

src/invidious/views/watch.ecr

@@ -102,11 +102,13 @@
             </p>
 
             <% if user %>
+                <% playlists = PG_DB.query_all("SELECT id,title FROM playlists WHERE author = $1", user.email, as: {String, String}) %>
+                <% if !playlists.empty? %>
                     <form data-onsubmit="return_false" class="pure-form pure-form-stacked" action="/playlist_ajax" method="post">
                         <div class="pure-control-group">
                             <label for="playlist_id"><%= translate(locale, "Add to playlist: ") %></label>
                             <select style="width:100%" name="playlist_id" id="playlist_id">
-                            <% PG_DB.query_all("SELECT id,title FROM playlists WHERE author = $1", user.email, as: {String, String}).each do |plid, title| %>
+                                <% playlists.each do |plid, title| %>
                                     <option data-plid="<%= plid %>" value="<%= plid %>"><%= title %></option>
                                 <% end %>
                             </select>
@@ -125,6 +127,7 @@
                     </script>
                     <script src="/js/playlist_widget.js?v=<%= Time.utc.to_unix_ms %>"></script>
                 <% end %>
+            <% end %>
 
             <% if CONFIG.dmca_content.includes?(video.id) || CONFIG.disabled?("downloads") %>
                 <p><%= translate(locale, "Download is disabled.") %></p>