ospf6d: add lost lines to area config block

* ospf6_area.c
  * ospf6_area_config_write(): write filter-list, import-list and
    export-list lines
diff --git a/ospf6d/ospf6_area.c b/ospf6d/ospf6_area.c
index d73d996..0224fe6 100644
--- a/ospf6d/ospf6_area.c
+++ b/ospf6d/ospf6_area.c
@@ -419,6 +419,18 @@
           prefix2str (&range->prefix, buf, sizeof (buf));
           vty_out (vty, " area %s range %s%s", oa->name, buf, VNL);
         }
+      if (PREFIX_NAME_IN (oa))
+        vty_out (vty, " area %s filter-list prefix %s in%s",
+                 oa->name, PREFIX_NAME_IN (oa), VNL);
+      if (PREFIX_NAME_OUT (oa))
+        vty_out (vty, " area %s filter-list prefix %s out%s",
+                 oa->name, PREFIX_NAME_OUT (oa), VNL);
+      if (IMPORT_NAME (oa))
+        vty_out (vty, " area %s import-list %s%s",
+                 oa->name, IMPORT_NAME (oa), VNL);
+      if (EXPORT_NAME (oa))
+        vty_out (vty, " area %s export-list %s%s",
+                 oa->name, EXPORT_NAME (oa), VNL);
     }
 }