safeguard q parameter in template (#1037) (#1038)

Author: tomkralidis

pycsw/ogc/api/templates/items.html

@@ -87,7 +87,7 @@
       <div class="input-group mb-3"> 
         <input type="text" class="form-control" name="q" placeholder="Search" id="tbq" value="">
         <script>
-          $('#tbq').val(decodeURIComponent("{{ attrs['q'].replace('+',' ') }}"))
+          $('#tbq').val(decodeURIComponent("{{ attrs.get('q', '').replace('+',' ') }}"))
         </script>
         <input class="btn btn-outline-secondary" type="submit" value="Search"></input>
       </div>