Movie browser demo: Added a @skipIfNull directive for demonstration purposes

Author: Aklakan

docs/demos/movies/index.html

@@ -163,7 +163,7 @@ <h1 style="display: inline; margin-right: 20px;">Wikidata Movie Browser</h1>
     netflix     @one @pattern(of: "SELECT ?s ?id { ?s wdt:P1874 ?o . BIND(IRI(CONCAT('https://www.netflix.com/title/', STR(?o))) AS ?id) }")
 
     # Pick the minimum advised viewing age based on "wdt:P2899" across any rating scheme
-    minAge      @one @pattern(of: "SELECT ?s (MIN(?o) AS ?age) { ?s (!<p>)/wdt:P2899 ?o } GROUP BY ?s")
+    minAge      @one @pattern(of: "SELECT ?s (MIN(?o) AS ?age) { ?s (!<p>)/wdt:P2899 ?o } GROUP BY ?s") @skipIfNull
 
     genres           @pattern(of: "SELECT DISTINCT ?s (STR(?l) AS ?x) { ?s wdt:P136/rdfs:label ?l . FILTER(langMatches(lang(?l), 'en')) }")
   }