fix related video author when id is empty

src/invidious/views/watch.ecr

@@ -346,7 +346,7 @@ we're going to need to do it here in order to allow for translations.
 
                             <h5 class="pure-g">
                                 <div class="pure-u-14-24">
-                                    <% if rv["ucid"]? %>
+                                    <% if !rv["ucid"].empty? %>
                                         <b style="width:100%"><a href="/channel/<%= rv["ucid"] %>"><%= rv["author"]? %><% if rv["author_verified"]? == "true" %>&nbsp;<i class="icon ion ion-md-checkmark-circle"></i><% end %></a></b>
                                     <% else %>
                                         <b style="width:100%"><%= rv["author"]? %><% if rv["author_verified"]? == "true" %>&nbsp;<i class="icon ion ion-md-checkmark-circle"></i><% end %></b>