hash table UPDATE optional cb for HT free

Allows freeing items in the hash table.
diff --git a/src/validation.c b/src/validation.c
index 6db020a..3ee600e 100644
--- a/src/validation.c
+++ b/src/validation.c
@@ -1246,7 +1246,7 @@
             /* failed when allocating uniquetables[j], following j are not allocated */
             break;
         }
-        lyht_free(uniqtables[v]);
+        lyht_free(uniqtables[v], NULL);
     }
     free(uniqtables);