Fix usage of enable_search_shortcuts theme config value.

The option value is not properly propagated to Java script.

sphinx/themes/basic/static/documentation_options.js_t

@@ -10,5 +10,5 @@ var DOCUMENTATION_OPTIONS = {
     SOURCELINK_SUFFIX: '{{ sourcelink_suffix }}',
     NAVIGATION_WITH_KEYS: {{ 'true' if theme_navigation_with_keys|tobool else 'false'}},
     SHOW_SEARCH_SUMMARY: {{ 'true' if show_search_summary else 'false' }},
-    ENABLE_SEARCH_SHORTCUTS: {{ 'true' if enable_search_shortcuts|tobool else 'false'}},
+    ENABLE_SEARCH_SHORTCUTS: {{ 'true' if theme_enable_search_shortcuts|tobool else 'false'}},
 };