Add new variable to uninstall hook.

islandora.install

@@ -55,6 +55,7 @@ function islandora_uninstall() {
     'islandora_namespace_restriction_enforced',
     'islandora_pids_allowed',
     'islandora_risearch_use_itql_when_necessary',
+    'islandora_require_obj_upload',
   );
   array_walk($variables, 'variable_del');
 }