virStoragePoolDefFree: Free @def->refresh

In 669018bc I've introduced def->refresh which might be
allocated by virStoragePoolDefRefreshParse() but is never freed.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/conf/storage_conf.c

@@ -509,6 +509,7 @@ virStoragePoolDefFree(virStoragePoolDefPtr def)
 
     VIR_FREE(def->target.path);
     VIR_FREE(def->target.perms.label);
+    VIR_FREE(def->refresh);
     if (def->namespaceData && def->ns.free)
         (def->ns.free)(def->namespaceData);
     VIR_FREE(def);