[views] fix boolean value

previously bool value was 0 or 1 it seems that elasticsearch 6 will not cast
this value anymore

cubicweb_elasticsearch/views.py

@@ -101,9 +101,15 @@ class ElasticSearchView(StartupView):
             if key.startswith('es_'):
                 # FIXME TODO have better typing mechanisme (inspect facets?)
                 try:
-                    facet_selections[key.replace('es_', '')] = int(value)
+                    if value.lower() == 'true':
+                        value = True
+                    elif value.lower() == 'false':
+                        value = False
+                    else:
+                        value = int(value)
                 except ValueError:
-                    facet_selections[key.replace('es_', '')] = value
+                    pass
+                facet_selections[key.replace('es_', '')] = value
             if key == 'page':
                 try:
                     start = (max(int(value) - 1, 0)) * 10